FlyBase Gene Report: Dmel\Nrx-IV

FB2026_01 , released March 12, 2026

FB2026_01 , released March 12, 2026

Gene: Dmel\Nrx-IV

General Information

Symbol

Dmel\Nrx-IV

Species

D. melanogaster

Name

Neurexin IV

Annotation Symbol

CG6827

Feature Type

protein_coding_gene

FlyBase ID

FBgn0013997

Gene Model Status

Stock Availability

22 publicly available

Gene Summary

Neurexin IV (Nrx-IV) encodes a transmembrane protein that is critical for septate junction formation in epithelia and between ensheathing glial cells and neurons. [Date last reviewed: 2019-03-14] (FlyBase Gene Snapshot)

All Summaries

Gene Snapshot
Alliance
Auto summary
UniProtKB
Interactive Fly

Also Known As

Nrx, NrxIV, nrx IV, neurexin, Dnrx

Key Links

Genomic Location

Cytogenetic map

Sequence location

3L:12,146,519..12,156,990 [+]

Recombination map

3-38

RefSeq locus

NT_037436 REGION:12146519..12156990

Sequence

Get Decorated FASTA

Genomic Maps

Other Genome Views

The following external sites may use different assemblies or annotations than FlyBase.

Function

Gene Ontology (GO) Annotations (19 terms)

Molecular Function (0 terms)

Terms Based on Experimental Evidence (0 terms)

Terms Based on Predictions or Assertions (0 terms)

Biological Process (15 terms)

Terms Based on Experimental Evidence (11 terms)

CV Term

Evidence

References

involved_in axon ensheathment

inferred from mutant phenotype

(Banerjee et al., 2006)

involved_in cell adhesion involved in heart morphogenesis

inferred from mutant phenotype

(Yi et al., 2008)

involved_in dorsal closure

inferred from mutant phenotype

(Schulte et al., 2003)

involved_in establishment of glial blood-brain barrier

inferred from mutant phenotype

(Stork et al., 2008, Schwabe et al., 2005)

involved_in heart process

inferred from mutant phenotype

(Yi et al., 2008)

involved_in nerve maturation

inferred from mutant phenotype

(Banerjee et al., 2006)

involved_in presynaptic membrane assembly

inferred from mutant phenotype

(Zweier et al., 2009)

involved_in regulation of tube size, open tracheal system

inferred from mutant phenotype

(Paul et al., 2003)

involved_in septate junction assembly

inferred from mutant phenotype

(Banerjee et al., 2006)

involved_in synaptic target recognition

inferred from mutant phenotype

(Kurusu et al., 2008)

involved_in terminal button organization

inferred from mutant phenotype

(McNeill et al., 2020)

inferred from mutant phenotype

(Zweier et al., 2009)

Terms Based on Predictions or Assertions (4 terms)

CV Term

Evidence

References

involved_in cell-cell junction organization

traceable author statement

(Harden, 2002)

involved_in intracellular protein localization

traceable author statement

(Cereijido et al., 2003, Noselli and Agnes, 1999)

involved_in nervous system development

inferred from biological aspect of ancestor with PANTHER:PTN000804946

(GO Reference Genome Project, 2011-)

involved_in signal transduction

inferred from biological aspect of ancestor with PANTHER:PTN002309037

(GO Reference Genome Project, 2011-)

Cellular Component (4 terms)

Terms Based on Experimental Evidence (4 terms)

CV Term

Evidence

References

located_in plasma membrane

inferred from high throughput direct assay

(Lye et al., 2014)

inferred from direct assay

(Yi et al., 2008)

located_in pleated septate junction

inferred from direct assay

(Faivre-Sarrailh et al., 2004)

located_in presynaptic active zone

inferred from direct assay

(Zweier et al., 2009)

located_in synapse

inferred from direct assay

(Zweier et al., 2009)

Terms Based on Predictions or Assertions (2 terms)

CV Term

Evidence

References

is_active_in plasma membrane

inferred from biological aspect of ancestor with PANTHER:PTN002309037

(GO Reference Genome Project, 2011-)

is_active_in synapse

inferred from biological aspect of ancestor with PANTHER:PTN000013648

(GO Reference Genome Project, 2011-)

Gene Group (FlyBase)

Protein Family (UniProt)

Belongs to the neurexin family. (Q94887)

Protein Signatures (InterPro)

Summaries

Gene Snapshot

Neurexin IV (Nrx-IV) encodes a transmembrane protein that is critical for septate junction formation in epithelia and between ensheathing glial cells and neurons. [Date last reviewed: 2019-03-14]

Protein Function (UniProtKB)

Seems to play a role in the formation and function of septate junctions. Septate junctions, which are the equivalent of vertebrates tight junctions, are characterized by regular arrays of transverse structures that span the intermembrane space and form a physical barrier to diffusion. Required for the blood-brain barrier formation.

(UniProt, Q94887)

Summary (Interactive Fly)

multifunctional protein required for structural integrity of septate junctions

Interactive Fly

Gene Model and Products

Number of Transcripts

2

Number of Unique Polypeptides

2

Please see the JBrowse view of Dmel\Nrx-IV for information on other features

To submit a correction to a gene model please use the Contact FlyBase form

Protein Domains (via Pfam)

Isoform displayed:

Pfam protein domains

InterPro name

classification

start

end

Protein Domains (via SMART)

Isoform displayed:

SMART protein domains

InterPro name

classification

start

end

Structure

Protein 3D structure (Predicted by AlphaFold) (AlphaFold entry Q94887)

If you don't see a structure in the viewer, refresh your browser.

Model Confidence:

Very high (pLDDT > 90)
Confident (90 > pLDDT > 70)
Low (70 > pLDDT > 50)
Very low (pLDDT < 50)

AlphaFold produces a per-residue confidence score (pLDDT) between 0 and 100. Some regions with low pLDDT may be unstructured in isolation.

Experimentally Determined Structures

Crossreferences

Comments on Gene Model

Low-frequency RNA-Seq exon junction(s) not annotated.

Gene model reviewed during 5.46

Transcript Data

Annotated Transcripts

Name

FlyBase ID

RefSeq ID

Length (nt)

Assoc. CDS (aa)

FBtr0075998

4940

1284

FBtr0075999

4940

1284

Additional Transcript Data and Comments

Reported size (kB)

5.0 (northern blot)

(Baumgartner et al., 1996)

Comments

External Data

Crossreferences

Polypeptide Data

Annotated Polypeptides

Name

FlyBase ID

Predicted MW (kDa)

Length (aa)

Theoretical pI

UniProt

RefSeq ID

GenBank

FBpp0075730

145.5

1284

6.38

FBpp0075731

145.1

1284

6.48

Polypeptides with Identical Sequences

None of the polypeptides share 100% sequence identity.

Additional Polypeptide Data and Comments

Reported size (kDa)

1283 (aa); 150-155 (kD observed); 145 (kD predicted)

(Baumgartner et al., 1996)

Comments

External Data

Subunit Structure (UniProtKB)

Forms a complex with Nrg and Cont (PubMed:15459097). Forms a complex composed of septa junction proteins Nrx-IV/Nrx, Tsf2/MTf, Cont and Nrg during late embryogenesis (PubMed:20935638). The C-terminal region interacts with coracle (PubMed:9508778). Interacts with Patj in cis form (PubMed:10102271).

(UniProt, Q94887)

Crossreferences

InterPro - A database of protein families, domains and functional sites

Linkouts

Sequences Consistent with the Gene Model

Nucleotide / Polypeptide Records

Mapped Features

Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\Nrx-IV using the Feature Mapper tool.

External Data

Crossreferences

Eukaryotic Promoter Database - A collection of databases of experimentally validated promoters for selected model organisms.

Nrx-IV_1

Linkouts

Expression Data

Testis-specificity index

The testis specificity index was calculated from modENCODE tissue expression data by Vedelek et al., 2018 to indicate the degree of testis enrichment compared to other tissues. Scores range from -2.52 (underrepresented) to 5.2 (very high testis bias).

-0.49

Transcript Expression

in situ

Stage

Tissue/Position (including subcellular localization)

Reference

embryonic stage 11 -- 17

embryonic/larval esophagus

(Baumgartner et al., 1996)

(Baumgartner et al., 1996)

northern blot

Stage

Tissue/Position (including subcellular localization)

Reference

embryonic stage -- adult stage

(Baumgartner et al., 1996)

RT-PCR

Stage

Tissue/Position (including subcellular localization)

Reference

embryonic stage

larval glial cell | intense

Comment: exons 3 and 4

(Rodrigues et al., 2012)

larval neuron | faint

Comment: exon 3

(Rodrigues et al., 2012)

larval neuron | intense

Comment: exon 4

(Rodrigues et al., 2012)

embryonic stage 16

Comment: specific to Nrx-IV-RA

(Rodrigues et al., 2012)

larval glial cell

Comment: specific to Nrx-IV-RB

(Rodrigues et al., 2012)

Additional Descriptive Data

Both exon 3 and 4 of Nrx-IV are detected via RT-PCR in embryonic glial cells. In embryonic neurons expression of exon 4 is more intense than of exon 3.

(Rodrigues et al., 2012)

Nrx-IV transcripts are differentially expressed in a tissue-specific manner. In late embryos and larvae, Nrx-IV-RA transcript ("exon 4" isoform) is preferentiatially expressed in neurons, while Nrx-IV-RB ("exon 3" isoform) is expressed in glia.

(Rodrigues et al., 2012)

Nrx transcripts are detected on northern blots at all stages of development tested except third instar larvae and peak in 6-18hr embryos. Transcripts are localized by in situ hybridization to epithelial cells of ectodermal origin beginning at embryonic stage 11. This includes cells of the epidermis, tracheal system, pharynx, esophagus, proventriculus, hindgut, salivary glands, PNS and CNS. In the PNS, staining is restricted to the scolopales of the lateral chordotonal organs and is restricted to glial cells. All tissues that express Nrx in the embyro are characterized by the presence of pleated septate junctions (pSJs). Nrx expression is first detected ~1hr before pSJ formation.

(Baumgartner et al., 1996)

Marker for

Subcellular Localization

CV Term

Polypeptide Expression

immunolocalization

Stage

Tissue/Position (including subcellular localization)

Reference

embryonic stage

lateral ectoderm

• basolateral plasma membrane

(Boettner et al., 2003)

lateral ectoderm

• lateral plasma membrane

(Boettner et al., 2003)

embryonic stage 15

midline glial cell

(Strigini et al., 2006)

exit glial cell

(Strigini et al., 2006)

embryonic stage 16

embryonic/larval hindgut

• basolateral plasma membrane | apical of septate junction

(Syed et al., 2011)

glial cell | subset of larval peripheral nervous system

• plasma membrane

(Banerjee et al., 2006)

chordotonal organ | restricted

(Banerjee et al., 2006)

(Banerjee et al., 2006)

scolopidial dendritic cap cell

(Banerjee et al., 2006)

third instar larval stage

embryonic/larval CNS subperineurial glial cell

(Zülbahar et al., 2018)

border follicle cell

(Wang et al., 2006)

mass spectroscopy

Stage

Tissue/Position (including subcellular localization)

Reference

• membrane

(Aradska et al., 2015)

Additional Descriptive Data

Nrx-IV protein is expressed in a short apical stretch of the basolateral membrane of embryonic septate junctions in the embryonic hindgut.

(Syed et al., 2011)

Nrx-IV protein is detected in the glial cell membranes in the peripheral nerves, ensheathing the axons. In the chordotonal organs, it is detected in the scolopale and cap cells.

(Banerjee et al., 2006)

Nrx protein was detected on all pleated septate junctions documented.

(Wang et al., 2006, Baumgartner et al., 1996)

Marker for

embryonic/larval CNS perineurial glial cell

(Zülbahar et al., 2018)

exit glial cell

(Strigini et al., 2006)

midline glial cell

(Strigini et al., 2006)

Subcellular Localization

CV Term

Evidence

References

located_in plasma membrane

inferred from high throughput direct assay

(Lye et al., 2014)

inferred from direct assay

(Yi et al., 2008)

located_in pleated septate junction

inferred from direct assay

(Faivre-Sarrailh et al., 2004)

located_in presynaptic active zone

inferred from direct assay

(Zweier et al., 2009)

located_in synapse

inferred from direct assay

(Zweier et al., 2009)

Expression Deduced from Reporters

Reporter: P{PTT-GA}Nrx-IV^CA06597

Stage

Tissue/Position (including subcellular localization)

Reference

first instar larval stage

embryonic/larval CNS perineurial glial cell

• septate junction

(Unhavaithaya and Orr-Weaver, 2012)

Reporter: P{PTT-un}Nrx-IV^PTT

Stage

Tissue/Position (including subcellular localization)

Reference

embryonic stage 16

ectoderm | restricted

(Edenfeld et al., 2006)

larval nervous system | restricted

(Edenfeld et al., 2006)

Reporter: PBac{681.P.FSVS-1}Nrx-IV^CPTI001977

Stage

Tissue/Position (including subcellular localization)

Reference

adult mushroom body

(Knowles-Barley, 2011.8.24)

(Knowles-Barley, 2011.8.24)

adult brain cell body rind

(Knowles-Barley, 2011.8.24)

adult gnathal ganglion | restricted

(Knowles-Barley, 2011.8.24)

High-Throughput Expression Data

Associated Tools

JBrowse - Visual display of RNA-Seq signals

View Dmel\Nrx-IV in JBrowse

RNA-Seq by Region - Search RNA-Seq expression levels by exon or genomic region

View exonic expression by developmental stage for Dmel\Nrx-IV

View exonic expression by tissue for Dmel\Nrx-IV

Bulk Downloads

RNA-Seq RPKM values for all genes

Reference

See Gelbart and Emmert, 2013 for analysis details and data files for all genes.

Developmental Proteome: Life Cycle

Developmental Proteome: Embryogenesis

External Data and Images

Linkouts

DRscDB - A single-cell RNA-seq resource for data mining and data comparison across species

39387/tissue=All

EMBL-EBI Single Cell Expression Atlas - Single cell expression across species

FBgn0013997

FlyAtlas - Adult expression by tissue, using Affymetrix Dros2 array

FBgn0013997

FlyAtlas2 - A Drosophila melanogaster expression atlas with RNA-Seq, miRNA-Seq and sex-specific data

FBgn0013997

Flygut - An atlas of the Drosophila adult midgut

FBgn0013997

Images

Image Based Resources

Alleles, Insertions, Transgenic Constructs, and Aberrations

Classical and Insertion Alleles ( 28 )

For All Classical and Insertion Alleles Show

Other relevant insertions

Transgenic Constructs ( 41 )

For All Alleles Carried on Transgenic Constructs Show

Transgenic constructs containing/affecting coding region of Nrx-IV

Transgenic constructs containing regulatory region of Nrx-IV

Aberrations (Deficiencies and Duplications) ( 15 )

Inferred from experimentation ( 15 )

Gene disrupted in

(Baumgartner et al., 1996)

(Ryder, 2004.4.26)

(Baumgartner et al., 1996, Hoogwerf et al., 1988)

(Hoogwerf et al., 1988)

(Hoogwerf et al., 1988)

(Baumgartner et al., 1996, Hoogwerf et al., 1988)

(Hoogwerf et al., 1988)

(Hoogwerf et al., 1988)

Gene not disrupted in

(Hoogwerf et al., 1988)

(Hoogwerf et al., 1988)

(Hoogwerf et al., 1988)

(Baumgartner et al., 1996, Hoogwerf et al., 1988)

(Hoogwerf et al., 1988)

(Hoogwerf et al., 1988)

Gene partially disrupted in

Df(3L)CRIMIC-CR71317

(Gene Disruption Project members, 2018-)

Inferred from location ( 6 )

Variants

Variant Molecular Consequences

Alleles Representing Disease-Implicated Variants

Phenotypes

For more details about a specific phenotype click on the relevant allele symbol.

Lethality

Allele

lethal, with Scer\GAL4^pnr-MD237

Nrx-IV^GD2436

lethal | recessive

lethal - all die during embryonic stage, with Scer\GAL4^Act5C.PI

Nrx-IV^GD2436

lethal - all die during embryonic stage, with Scer\GAL4^elav.PU

Nrx-IV^GD2436

Nrx-IV^CA06597

viable, with Dcr-2^UAS.cDa, Scer\GAL4^elav.PLu

Nrx-IV^GD2436

viable, with Scer\GAL4^Mef2.PR

Nrx-IV^GD2436

viable, with Scer\GAL4^tin.CΔ4

Nrx-IV^GD2436

Other Phenotypes

Allele

abnormal learning | adult stage

Nrx-IV^EP809

abnormal locomotor behavior | larval stage, with Scer\GAL4^Gli.PU

Nrx-IV^GD2436

abnormal neuroanatomy

Nrx-IV⁴⁰²⁵

abnormal neuroanatomy | embryonic stage, with Scer\GAL4^elav.PU

Nrx-IV^GD2436

abnormal neuroanatomy | larval stage, with Scer\GAL4^elav.PU

Nrx-IV^EP604

abnormal neuroanatomy | larval stage, with Scer\GAL4^elav-C155

Nrx-IV^EP809

abnormal neuroanatomy | larval stage, with Scer\GAL4^Gli.PU

Nrx-IV^GD2436

abnormal neurophysiology (with Df(3L)BK9)

abnormal neurophysiology | larval stage, with Scer\GAL4^Gli.PU

Nrx-IV^GD2436

decreased cell number | somatic clone | third instar larval stage

Nrx-IV^D56

increased size | larval stage, with Scer\GAL4^Gli.PU

Nrx-IV^GD2436

Phenotype manifest in

Allele

abdominal lateral pentascolopidial chordotonal organ lch5

Nrx-IV⁴³⁰⁴

anterior fascicle & synapse, with Scer\GAL4^elav-C155

Nrx-IV^EP809

anterior fascicle & synapse | supernumerary, with Scer\GAL4^elav-C155

Nrx-IV^EP809

axolemma & nerve

Nrx-IV⁴³⁰⁴

central nervous system

Nrx-IV⁴³⁰⁴

embryonic/first instar larval cuticle | dorsal

embryonic/larval salivary gland

Nrx-IV⁴³⁰⁴

embryonic/larval salivary gland | embryonic stage

embryonic epidermis | dorsal

Nrx-IV⁴⁶

embryonic ganglionic branch & embryonic tracheole (with Nrx-IV⁴⁰²⁵)

Nrx-IV⁴⁸⁶⁵

embryonic ganglionic branch & embryonic tracheole (with Nrx-IV⁴⁸⁶⁵)

Nrx-IV⁴⁰²⁵

epithelium | embryonic stage

germline cell | male, with Scer\GAL4^ptc-559.1

Nrx-IV^EP809

larval brain | larval stage, with Scer\GAL4^elav.PU

Nrx-IV^EP604

larval brain | somatic clone | third instar larval stage

Nrx-IV^D56

larval intersegmental nerve, with Scer\GAL4^elav-C155

Nrx-IV^EP809

larval ventral nerve cord | embryonic stage

Nrx-IV⁴³⁰⁴

midline glial cell | embryonic stage

Nrx-IV⁴³⁰⁴

nerve | larval stage, with Scer\GAL4^Gli.PU

Nrx-IV^GD2436

neuromuscular junction

NMJ bouton | larval stage, with Scer\GAL4^elav.PU

Nrx-IV^EP604

pleated septate junction

presumptive embryonic/larval tracheal system

Nrx-IV⁴³⁰⁴

presynaptic active zone | larval stage, with Scer\GAL4^elav.PU

Nrx-IV^EP604

Nrx-IV⁴³⁰⁴

scolopidium & abdominal lateral pentascolopidial chordotonal organ lch5

Nrx-IV⁴³⁰⁴

septate junction

Nrx-IV¹⁸¹⁷

septate junction & peripheral glial cell

Nrx-IV⁴³⁰⁴

tracheal dorsal trunk primordium (with Nrx-IV⁴⁰²⁵)

Nrx-IV⁴⁸⁶⁵

tracheal dorsal trunk primordium (with Nrx-IV⁴⁸⁶⁵)

Nrx-IV⁴⁰²⁵

Orthologs

Downloads

Download All DIOPT Orthologs

Human Orthologs (via DIOPT v9.1)

Species\Gene Symbol

Score

Best Score

Best Reverse Score

Source

Alignment

Complementation?

Transgene?

Homo sapiens (Human) (39)

12 of 14

Yes

Yes

11 of 14

No

Yes

1

11 of 14

No

Yes

11 of 14

No

Yes

11 of 14

No

Yes

11 of 14

No

Yes

4 of 14

No

Yes

2 of 14

No

No

5

2 of 14

No

No

2 of 14

No

No

1 of 14

No

No

1 of 14

No

No

1 of 14

No

No

1 of 14

No

No

1 of 14

No

No

1

1 of 14

No

No

6

1 of 14

No

No

1 of 14

No

Yes

1 of 14

No

Yes

1 of 14

No

No

1 of 14

No

No

1 of 14

No

No

1

1 of 14

No

No

1 of 14

No

No

1 of 14

No

No

0

1 of 14

No

No

1 of 14

No

Yes

1 of 14

No

No

1 of 14

No

No

1 of 14

No

No

1 of 14

No

No

1 of 14

No

Yes

1

1 of 14

No

No

1 of 14

No

Yes

1 of 14

No

Yes

1 of 14

No

No

1 of 14

No

No

1 of 14

No

No

1 of 14

No

No

Model Organism Orthologs (via DIOPT v9.1)

Species\Gene Symbol

Score

Best Score

Best Reverse Score

Source

Alignment

Complementation?

Transgene?

Rattus norvegicus (Norway rat) (24)

11 of 14

Yes

Yes

11 of 14

Yes

Yes

11 of 14

Yes

Yes

11 of 14

Yes

Yes

10 of 14

No

Yes

10 of 14

No

Yes

9 of 14

No

Yes

2 of 14

No

Yes

2 of 14

No

No

2 of 14

No

No

2 of 14

No

No

1 of 14

No

No

1 of 14

No

No

1 of 14

No

No

1 of 14

No

No

1 of 14

No

Yes

1 of 14

No

Yes

1 of 14

No

No

1 of 14

No

Yes

1 of 14

No

No

1 of 14

No

No

1 of 14

No

Yes

1 of 14

No

Yes

1 of 14

No

No

Mus musculus (laboratory mouse) (25)

12 of 14

Yes

Yes

11 of 14

No

Yes

11 of 14

No

Yes

11 of 14

No

Yes

11 of 14

No

Yes

10 of 14

No

Yes

10 of 14

No

Yes

2 of 14

No

No

2 of 14

No

No

2 of 14

No

No

1 of 14

No

No

1 of 14

No

No

1 of 14

No

No

1 of 14

No

Yes

1 of 14

No

Yes

1 of 14

No

No

1 of 14

No

Yes

1 of 14

No

Yes

1 of 14

No

No

1 of 14

No

No

1 of 14

No

No

1 of 14

No

Yes

2

1 of 14

No

Yes

1 of 14

No

No

1 of 14

No

No

Xenopus tropicalis (Western clawed frog) (21)

9 of 13

Yes

Yes

9 of 13

Yes

Yes

7 of 13

No

Yes

6 of 13

No

Yes

1 of 13

No

No

1 of 13

No

No

1 of 13

No

No

1 of 13

No

No

1 of 13

No

No

1 of 13

No

No

1 of 13

No

No

1 of 13

No

No

1 of 13

No

No

Xtro\LOC100490929

1 of 13

No

No

1 of 13

No

Yes

1 of 13

No

No

1 of 13

No

Yes

1 of 13

No

No

1 of 13

No

No

1 of 13

No

No

1 of 13

No

Yes

Danio rerio (Zebrafish) (31)

11 of 14

Yes

Yes

11 of 14

Yes

Yes

11 of 14

Yes

Yes

11 of 14

Yes

Yes

11 of 14

Yes

Yes

10 of 14

No

Yes

9 of 14

No

Yes

2 of 14

No

No

2 of 14

No

No

2 of 14

No

No

2 of 14

No

No

2 of 14

No

No

1 of 14

No

No

1 of 14

No

No

1 of 14

No

No

1 of 14

No

No

1 of 14

No

No

1 of 14

No

No

1 of 14

No

Yes

1 of 14

No

Yes

1 of 14

No

No

1 of 14

No

No

1 of 14

No

Yes

1 of 14

No

No

Drer\LOC101883589

1 of 14

No

No

1 of 14

No

Yes

1 of 14

No

Yes

1 of 14

No

No

1 of 14

No

Yes

Drer\si:dkey-22o22.2

1 of 14

No

No

1 of 14

No

No

Caenorhabditis elegans (Nematode, roundworm) (8)

11 of 14

Yes

Yes

3 of 14

No

No

2 of 14

No

No

1 of 14

No

No

1 of 14

No

No

1 of 14

No

No

1 of 14

No

No

1 of 14

No

No

Anopheles gambiae (African malaria mosquito) (11)

Agam\AgaP_AGAP007545

11 of 12

Yes

Yes

Agam\AgaP_AGAP006513

3 of 12

No

No

Agam\AgaP_AGAP004066

2 of 12

No

No

Agam\AgaP_AGAP002793

1 of 12

No

No

Agam\AgaP_AGAP003656

1 of 12

No

No

Agam\AgaP_AGAP003873

1 of 12

No

No

Agam\AgaP_AGAP004993

1 of 12

No

No

Agam\AgaP_AGAP005714

1 of 12

No

No

Agam\AgaP_AGAP007924

1 of 12

No

No

Agam\AgaP_AGAP008400

1 of 12

No

No

1 of 12

No

No

Arabidopsis thaliana (thale-cress) (0)

Saccharomyces cerevisiae (Brewer's yeast) (0)

Schizosaccharomyces pombe (Fission yeast) (0)

Escherichia coli (enterobacterium) (0)

Other Organism Orthologs (via OrthoDB)

Data provided directly from OrthoDB:Nrx-IV. Refer to their site for version information.

Paralogs

Downloads

Download All DIOPT Paralogs

Paralogs (via DIOPT v9.1)

Gene Symbol

Score

Source

Alignment

Drosophila melanogaster (Fruit fly) (25)

4 of 13

4 of 13

1 of 13

1 of 13

1 of 13

1 of 13

1 of 13

1 of 13

1 of 13

1 of 13

1 of 13

1 of 13

1 of 13

1 of 13

1 of 13

1 of 13

1 of 13

1 of 13

1 of 13

1 of 13

1 of 13

1 of 13

1 of 13

1 of 13

1 of 13

Human Disease Associations

FlyBase Human Disease Model Reports

Pitt-Hopkins-like syndrome 1

Disease Ontology (DO) Annotations

Models Based on Experimental Evidence ( 2 )

Allele

Disease

Evidence

References

Nrx-IV⁴³⁰⁴

model of autism spectrum disorder

CEA

(Grice et al., 2015)

model of autosomal recessive intellectual developmental disorder

CEA

(Zweier et al., 2009)

Potential Models Based on Orthology ( 1 )

Human Ortholog

Disease

Evidence

References

CNTNAP2; contactin associated protein 2

model of cortical dysplasia-focal epilepsy syndrome

IEA

(FlyBase, 2019-)

Modifiers Based on Experimental Evidence ( 2 )

Allele

Disease

Interaction

References

Nrx-IV⁴³⁰⁴

exacerbates autism spectrum disorder

modeled by p120ctn³⁰⁸

(Grice et al., 2015)

model of autism spectrum disorder

is ameliorated by N^UAS.cGa

(Grice et al., 2015)

is exacerbated by p120ctn³⁰⁸

(Grice et al., 2015)

exacerbates Machado-Joseph disease

modeled by Hsap\ATXN3^{tr.Q78.UAS.Tag:HA}

(Voßfeldt et al., 2012)

Disease Associations of Human Orthologs (via DIOPT v9.1 and OMIM)

Note that ortholog calls supported by only 1 or 2 algorithms (DIOPT score < 3) are not shown.

Homo sapiens (Human)

Gene name

Score

OMIM

OMIM Phenotype

DO term

Complementation?

Transgene?

CNTNAP2; contactin associated protein 2

12 of 14

cortical dysplasia-focal epilepsy syndrome

CNTNAP1; contactin associated protein 1

11 of 14

CNTNAP3B; contactin associated protein family member 3B

11 of 14

CNTNAP3; contactin associated protein family member 3

11 of 14

CNTNAP4; contactin associated protein family member 4

11 of 14

CNTNAP5; contactin associated protein family member 5

11 of 14

CNTNAP3C; contactin associated protein family member 3C

4 of 14

Functional Complementation Data

Functional complementation data is computed by FlyBase using a combination of the orthology data obtained from DIOPT and OrthoDB and the allele-level genetic interaction data curated from the literature.

Interactions

Summary of Physical Interactions

Interaction Browsers

View in FlyBase Interactions Browser View in MIST tool (external link)

Please see the Physical Interaction reports below for full details

protein-protein

Physical Interaction

Assay

References

anti bait coimmunoprecipitation, western blot, anti tag western blot

(Banerjee et al., 2011, Tiklová et al., 2010, Banerjee et al., 2006, Faivre-Sarrailh et al., 2004)

anti tag coimmunoprecipitation, western blot

(Schulte et al., 2006)

anti bait coimmunoprecipitation, western blot

(Banerjee et al., 2006, Genova and Fehon, 2003)

two hybrid, pull down, western blot

(Bhat et al., 1999)

anti bait coimmunoprecipitation, western blot

(Tiklová et al., 2010)

anti bait coimmunoprecipitation, western blot

(Genova and Fehon, 2003)

anti bait coimmunoprecipitation, western blot

(Genova and Fehon, 2003)

anti bait coimmunoprecipitation, western blot

(Genova and Fehon, 2003)

pull down, western blot, anti tag coimmunoprecipitation

(Bachmann et al., 2008)

Nrx-IV - wrapper

bead aggregation assay, fluorescence microscopy, inferred by author, anti tag coimmunoprecipitation, western blot

(Slováková and Carmena, 2011, Stork et al., 2009, Wheeler et al., 2009)

RNA-protein

Physical Interaction

Assay

References

anti bait coimmunoprecipitation, primer specific pcr, anti tag coimmunoprecipitation, molecular weight estimation by staining, pull down, anti tag western blot

(Giuliani et al., 2014, Edenfeld et al., 2006)

RNA-RNA

Physical Interaction

Assay

References

Nrx-IV - mir-184

immunohistochemistry, luminiscence technology

(Sharifkhodaei et al., 2016, Iovino et al., 2009, Kertesz et al., 2007)

Summary of Genetic Interactions

Interaction Browsers

Starting gene(s)

Interaction type

Interacting gene(s)

Reference

Starting gene(s)

Interaction type

Interacting gene(s)

Reference

External Data

Subunit Structure (UniProtKB)

Forms a complex with Nrg and Cont (PubMed:15459097). Forms a complex composed of septa junction proteins Nrx-IV/Nrx, Tsf2/MTf, Cont and Nrg during late embryogenesis (PubMed:20935638). The C-terminal region interacts with coracle (PubMed:9508778). Interacts with Patj in cis form (PubMed:10102271).

(UniProt, Q94887 )

Linkouts

BioGRID - A database of protein and genetic interactions.

64741

DroID - A comprehensive database of gene and protein interactions.

FBgn0013997

MIST (protein-protein) - An integrated Molecular Interaction Database

39387

Pathways

Signaling Pathways (FlyBase)

Metabolic Pathways

FlyBase

External Links

External Data

Linkouts

Class of Gene

protein_coding_gene

Genomic Location and Detailed Mapping Data

Chromosome (arm)

3L

Recombination map

3-38

Cytogenetic map

Sequence location

3L:12,146,519..12,156,990 [+]

FlyBase Computed Cytological Location

Cytogenetic map

Evidence for location

68F6-68F7

Limits computationally determined from genome sequence between P{PZ}rols⁰⁸²³²&P{lacW}l(3)j2D3^j2D3 and P{PZ}l(3)05088⁰⁵⁰⁸⁸

Experimentally Determined Cytological Location

Cytogenetic map

Notes

References

36D-36D

(Lloyd et al., 2000)

68F-68F

(Baumgartner, 1995.4.26)

68F-68F

(determined by in situ hybridisation)

(Baumgartner, 1995)

Determined by comparing Celera genomic sequence with sequence from BDGP BAC and P1 clones.

(Lloyd et al., 2000)

Experimentally Determined Recombination Data

Location

3-38

(FlyBase, 2016)

3-30.9

(Comeron et al., 2012)

3-

(Baumgartner, 1995.4.26)

Left of (cM)

Right of (cM)

Notes

Stocks and Reagents

Stocks (22)

Aberrations including deletions of this gene Aberrations including duplications of this gene

28715

y¹ v¹; P{TRiP.JF03142}attP2

50798

y¹ w^*; P{PTT-GA}Nrx-IV^CA06597

17185

w¹¹¹⁸; P{EP}Nrx-IV^EP604/TM3, Sb¹

602904

w^*; wg^Sp-1/CyO; P{PTT-un}Nrx-IV^PTT

54586

y¹ w^*; Dp(3;2)CH322-154P15, PBac{CH322-154P15}VK00037

92348

y¹ w¹¹¹⁸; PBac{CH322-154P15-NrxIV-C-mCh.BlastR}VK00033

38192

y¹ sc^* v¹ sev²¹; P{TRiP.GL00631}attP40

115251

w¹¹¹⁸; PBac{681.P.FSVS-1}Nrx-IV^CPTI001977

v108128

P{KK102207}VIE-260B

v8353

w¹¹¹⁸; P{GD2436}v8353

v9039

w¹¹¹⁸; P{GD2436}v9039

v342137

P{hsFLP}1, y¹ w¹¹¹⁸; P{HD_CFD01637}attP40/CyO-GFP

More stocks available...

Genomic Clones (16)

Please Note FlyBase no longer curates genomic clone accessions so this list may not be complete

cDNA Clones (78)

Please Note This section lists cDNAs and ESTs that fall within the genomic extent of the gene model, which may include cDNAs and ESTs of genes within introns, or of overlapping genes. Please see JBrowse for alignment of the cDNAs and ESTs to the gene model.

cDNA clones, fully sequenced

BDGP DGC clones

RE18634

Other clones

FI12817

Drosophila Genomics Resource Center cDNA clones

For each fully sequenced cDNA the DGRC maintains various forms of the cDNA (e.g tagged or untagged) in several different host vectors for subsequent cloning and expression in Drosophila and Drosophila cell lines.

FBgn0013997

cDNA Clones, End Sequenced (ESTs)

BDGP DGC clones

Other clones

RNAi and Array Information

Linkouts

DRSC - Results frm RNAi screens

FBgn0013997

Antibody Information

Laboratory Generated Antibodies

polyclonal

(Baumgartner et al., 1996)

Commercially Available Antibodies

Cell Line Information

Publicly Available Cell Lines

Other Stable Cell Lines

Other Comments

Proper targetting of pck gene product to the pleated septate junctions in the tracheal system depends on Nrx-IV and cora but not Fas3.

(Behr et al., 2003)

dsRNA made from templates generated with primers directed against this gene tested in RNAi screen for effects on Kc167 and S2R⁺ cell morphology.

(Kiger et al., 2003)

The amino-terminal 383 amino acids of cora (a functional domain that is both necessary and sufficient for proper septate junction localisation of cora) and the cytoplasmic domain of Nrx-IV interact directly.

(Ward et al., 1998)

Complementation groups l(3)68Fa, l(3)68Fb, l(3)68Fc, l(3)68Fd, l(3)68Fe, Nrx-IV, l(3)69Aa and l(3)69Ab isolated by Hoogwerf et al. (FBrf0048238) probably correspond to complementation groups l(3)68Fg, l(3)j2D3, l(3)68Fh, rols, l(3)68Fi, Nrx-IV, l(3)69Ah and l(3)69Ai isolated by Baumgartner at al, 1996, Cell 87: 1059--1068, but a one to one correspondence cannot be made as Hoogwerf mutations are apparently lost.

(Bellen, 1997.1.14)

P{nrx⁺} transformant chromosomes fully rescue the embryonic lethality of l(3)68Ff mutations, demonstrating l(3)68Ff and Nrx-IV are the same complementation group.

(Baumgartner et al., 1996)

Nrx-IV is a transmembrane protein of the septate junction and is required in the formation of septate-junction septa and intercellular barriers.

(Baumgartner et al., 1996)

Identified in a PCR screen for homologues of the vertebrate neurexin.

(Baumgartner et al., 1995)

PCR-primers from the EGF-like region of chicken tenascin have been used to amplify Nrx-IV, Nrx-IV shows high homology to the EGF domain.

(Baumgartner et al., 1995)

Nrx-IV has a transcript of 5.0 kb, and encodes a protein of 1283 aa. The protein has an apparent molecular weight of about 155kD, with a domain structure almost identical to vertebrate neurexin.

(Baumgartner, 1995.6.22)

Relationship to Other Genes

Source for database merge of

Additional comments

Nomenclature History

Source for database identify of

Source for identity of: Nrx CG6827

(Zhang, 1999.11)

Nomenclature comments

Etymology

Synonyms and Secondary IDs (32)

Reported As

Symbol Synonym

CG682

(Lee et al., 2013)

CG6827

(Aradska et al., 2015, Hosono et al., 2015, Christis and Munro, 2012, Voßfeldt et al., 2012, Khanna et al., 2010, Ni et al., 2010.12.1, Keleman et al., 2009.8.5, Perkins et al., 2009, Zweier et al., 2009, Kraut et al., 2001, Kraut et al., 2001)

CNTNAP2

(Dalla Vecchia et al., 2019)

CT21123

(Hynes and Zhao, 2000)

Dnrx

(Yuan and Ganetzky, 1998, Littleton et al., 1995)

NRX

(Genova and Fehon, 2003, Müller and Bossinger, 2003)

NRX IV

(Bhat et al., 1999, Bhat et al., 1999, Yuan and Ganetzky, 1999, Littlejohn et al., 1997)

Nrx

(Nelson et al., 2010, Tiklova et al., 2010, Tiklová et al., 2010, Alves-Silva et al., 2008, Schotman et al., 2008, Gorfinkiel and Arias, 2007, Kertesz et al., 2007, Furuse and Tsukita, 2006, Ng et al., 2006, Schneider et al., 2006, Schulte et al., 2006, Strigini et al., 2006, Wang et al., 2006, Schwabe et al., 2005, Wu et al., 2005, Dudu et al., 2004, Llimargas et al., 2004, Schulz et al., 2004, Wu and Beitel, 2004, Zeitler et al., 2004, Behr et al., 2003, Boettner et al., 2003, Genova and Fehon, 2003, Schulte et al., 2003, Tanentzapf and Tepass, 2003, Harden, 2002, Jasper et al., 2002, Magie et al., 2002, Wayne and McIntyre, 2002, Whitfield et al., 2002, Bilder, 2001, Bilder, 2001, Fuss et al., 2001, Bilder and Perrimon, 2000, Hoover and Bryant, 2000, Liu and Lengyel, 2000, Lloyd et al., 2000, Muller, 2000, Zhang et al., 2000, Goberdhan and Wilson, 1998, Lamb et al., 1998, Ward et al., 1998, Bellen, 1997.1.14, Bryant, 1997, Ward and Fehon, 1997, Ward and Fehon, 1997, Baumgartner, 1995, Baumgartner, 1995.6.22, Baumgartner et al., 1995, Baumgartner et al., 1995)

Nrx IV

(Banerjee et al., 2008, Laval et al., 2008, Banerjee et al., 2006, Hemphala et al., 2003, Bellen et al., 1998, Bhat et al., 1998)

Nrx-IV

(Wang et al., 2025, Zechini et al., 2025, Jang et al., 2024, Lee et al., 2024, Banach-Latapy et al., 2023, Barbaste et al., 2023, Titlow et al., 2023, Adashev et al., 2022, De et al., 2022, Pegoraro et al., 2022, Wang et al., 2022, Alhadyian et al., 2021, Rice et al., 2021, Chou et al., 2020, Jevitt et al., 2020, Lee et al., 2020, McNeill et al., 2020, Hope et al., 2019, Jiang et al., 2019, Lim et al., 2019, Ueoka et al., 2019, Ansar et al., 2018, Carvalho et al., 2018, Gene Disruption Project members, 2018-, Flores-Benitez and Knust, 2016, Shen et al., 2016, Aradska et al., 2015, de Madrid et al., 2015, Grice et al., 2015, Morozova et al., 2015, Bätz et al., 2014, Hall et al., 2014, Felix et al., 2012, Rodrigues et al., 2012, Unhavaithaya and Orr-Weaver, 2012, Venables et al., 2012, Voßfeldt et al., 2012, Guan et al., 2011, Laprise and Tepass, 2011, Slováková and Carmena, 2011, Arancio et al., 2010, Laprise et al., 2010, Nilton et al., 2010, Hijazi et al., 2009, Iovino et al., 2009, Laprise et al., 2009, Stork et al., 2009, Venken et al., 2009, Wheeler et al., 2009, Zweier et al., 2009, Moyer and Jacobs, 2008, Yi et al., 2008, Buszczak et al., 2007)

Nrx4

(Glashauser et al., 2023)

Nx IV

(Missler and Sudhof, 1998)

l(3)68Ff

l(3)rsg23

neurexin

(Kamimura and Maeda, 2021)

nrx

(Guangming et al., 2020, Stork et al., 2009, Moyer and Jacobs, 2008, Wu et al., 2007, Edenfeld et al., 2006, Tonning et al., 2005, Wu et al., 2004, Cereijido et al., 2003, Paul et al., 2003, Agnes and Noselli, 1999, Noselli, 1998, Bhat et al., 1997, Bhat et al., 1997, Baumgartner et al., 1996, Baumgartner, 1995.4.26, Baumgartner et al., 1995)

nrx IV

(Long et al., 2025, Banerjee et al., 2011, Laval et al., 2008, Bhat, 2003, Faivre-Sarrailh et al., 2001, Jones, 2001, Andrew et al., 2000, Littleton, 2000, Noselli and Agnes, 1999)

nrx-IV

(Deligiannaki et al., 2015, Eddison et al., 2012, Moyer and Jacobs, 2008)

nrx-iv

(Rouka et al., 2021)

nrx4

(Gunderson et al., 2021)

nrxIV

(Morin-Poulard et al., 2021, Banerjee et al., 2017, Baumann et al., 2010, Stork et al., 2009, Stork et al., 2008, Salinas et al., 2001)

rsg23

(Hoogwerf et al., 1988)

Name Synonyms

Neurexin

(Finegan and Bergstralh, 2020, Ward and Fehon, 1997)

Neurexin 4

(Khanna et al., 2010)

Neurexin IV

(Markovich et al., 2024, Mira-Osuna and Borgne, 2024, Pogodalla et al., 2022, Alhadyian et al., 2021, Bittern et al., 2021, Jin et al., 2018, Stephens et al., 2018, Peterson and Krasnow, 2015, Lee et al., 2013, Brink et al., 2012, Ile et al., 2012, Schmidt et al., 2012, Khanna et al., 2010, Kim et al., 2010, Nilton et al., 2010, Tiklová et al., 2010, Chung et al., 2009, Hijazi et al., 2009, Jeon and Zinn, 2009, Laprise et al., 2009, Stork et al., 2009, Alves-Silva et al., 2008, Bachmann et al., 2008, Banerjee et al., 2008, Laval et al., 2008, Schotman et al., 2008, Tiklová et al., 2007, Ng et al., 2006, Schulte et al., 2006, Wang et al., 2006, Daneman and Barres, 2005, Zeitler et al., 2004, Nelson, 2003, Venema and Auld, 2003, Venema and Auld, 2003, Cantera et al., 2002, Fusse and Hoch, 2002, Bryant and Huwe, 2000, Baumgartner et al., 1998, Bellen et al., 1998, Tepass, 1997)

Neurexin-4

(Humbert et al., 2003)

Neurexin-IV

(Rodrigues et al., 2012, Unhavaithaya and Orr-Weaver, 2012, Venables et al., 2012, Yi et al., 2008)

NeurexinIV

(Leiserson and Keshishian, 2011, Rodrigues et al., 2011, Silies and Klämbt, 2011, Syed et al., 2011, Nelson et al., 2010, Moyer and Jacobs, 2008, Silies et al., 2007)

neurexin

(Slack et al., 2006, Bryant, 1997, Baumgartner et al., 1996)

neurexin IV

(Giuliani et al., 2014, Jaspers et al., 2012, Guan et al., 2011, Baumann et al., 2010, Kurusu et al., 2008, Gorfinkiel and Arias, 2007, Bhat, 2003, Paul et al., 2003, Tabuchi and Sudhof, 2002, Brophy, 2001, Andrew et al., 2000, Missler et al., 1998)

neurexinIV

(Stork et al., 2008, Edenfeld et al., 2006)

rose-gespleten region interval 23

(Hoogwerf et al., 1988)

Secondary FlyBase IDs

FBgn0002261

Datasets (0)

Study focus (0)

Experimental Role

Project

Project Type

Title

Study result (0)

Result

Result Type

Title

External Crossreferences and Linkouts ( 40 )

Sequence Crossreferences

NCBI Gene - Gene integrates information from a wide range of species. A record may include nomenclature, Reference Sequences (RefSeqs), maps, pathways, variations, phenotypes, and links to genome-, phenotype-, and locus-specific resources worldwide.

39387

GenBank Nucleotide - A collection of sequences from several sources, including GenBank, RefSeq, TPA, and PDB.

GenBank Protein - A collection of sequences from several sources, including translations from annotated coding regions in GenBank, RefSeq and TPA, as well as records from SwissProt, PIR, PRF, and PDB.

RefSeq - A comprehensive, integrated, non-redundant, well-annotated set of reference sequences including genomic, transcript, and protein.

UniProt/GCRP - The gene-centric reference proteome (GCRP) provides a 1:1 mapping between genes and UniProt accessions in which a single 'canonical' isoform represents the product(s) of each protein-coding gene.

Q94887

UniProt/Swiss-Prot - Manually annotated and reviewed records of protein sequence and functional information

Q94887

UniProt/TrEMBL - Automatically annotated and unreviewed records of protein sequence and functional information

Q8IQH0

Other crossreferences

AlphaFold DB - AlphaFold provides open access to protein structure predictions for the human proteome and other key proteins of interest, to accelerate scientific research.

Q94887

DRscDB - A single-cell RNA-seq resource for data mining and data comparison across species

39387/tissue=All

EMBL-EBI Single Cell Expression Atlas - Single cell expression across species

FBgn0013997

FlyAtlas2 - A Drosophila melanogaster expression atlas with RNA-Seq, miRNA-Seq and sex-specific data

FBgn0013997

FlyMine - An integrated database for Drosophila genomics

FBgn0013997

InterPro - A database of protein families, domains and functional sites

KEGG Genes - Molecular building blocks of life in the genomic space.

dme:Dmel_CG6827

MARRVEL_MODEL - MARRVEL (model organism gene)

39387

Linkouts

BioGRID - A database of protein and genetic interactions.

64741

Drosophila Genomics Resource Center - Drosophila Genomics Resource Center (DGRC) cDNA clones

FBgn0013997

DroID - A comprehensive database of gene and protein interactions.

FBgn0013997

DRSC - Results frm RNAi screens

FBgn0013997

Eukaryotic Promoter Database - A collection of databases of experimentally validated promoters for selected model organisms.

Nrx-IV_1

FlyAtlas - Adult expression by tissue, using Affymetrix Dros2 array

FBgn0013997

FlyCyc Genes - Genes from a BioCyc PGDB for Dmel

FBGN0013997

Flygut - An atlas of the Drosophila adult midgut

FBgn0013997

iBeetle-Base - RNAi phenotypes in the red flour beetle (Tribolium castaneum)

TC011252

Interactive Fly - A cyberspace guide to Drosophila development and metazoan evolution

Interactive Fly

MIST (protein-protein) - An integrated Molecular Interaction Database

39387

References (318)