FB2026_01 , released March 12, 2026
FB2026_01 , released March 12, 2026
Human Disease Model Report: Alzheimer disease, susceptibility to (postulated), SNRPN-related
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General Information
Name
Alzheimer disease, susceptibility to (postulated), SNRPN-related
FlyBase ID
FBhh0000281
Disease Ontology Term
Parent Disease
OMIM
Overview

Initially identified in an analysis of two genome-wide association studies (FBrf0223922), the human gene SNRPN is proposed as a candidate susceptibility locus for Alzheimer disease. SNRPN encodes a component of a small nuclear ribonucleoprotein complex. There is a single fly ortholog, SmB, for which RNAi-targeting constructs, and alleles caused by insertional mutagenesis have been generated. Dmel\SmB is orthologous to one additional human gene, SNRPB. SNRPN is also implicated in the disease Prader-Willi syndrome (MIM:176270), as one of several contiguous genes that contribute to that syndrome.

The SNRPN gene has not been introduced into flies.

The fly ortholog SmB was tested for genetic interaction with a transgenically introduced mutational variant of the human tau gene (Hsap\MAPT): RNAi-mediated reduction in the expression of SmB was observed to enhance the phenotype associated with tau toxicity; overexpression in the eye reduces the tau toxicity phenotype. Physical and genetic interactions of Dmel\SmB have been characterized; see below and in the gene report for SmB.

[updated June 2016 by FlyBase; FBrf0222196]

Disease Summary Information
Parent Disease Summary: Alzheimer disease
Symptoms and phenotype

Alzheimer disease (AD) is the most common form of progressive dementia in the elderly. [from MIM:104300; 2016.01.08]

(OMIM, 2013-)

Memory loss is the most common sign of Alzheimer disease. As the disorder progresses, some people with AD experience personality and behavioral changes; other common symptoms include agitation, restlessness, withdrawal, and loss of language skills. Total care is usually required during the advanced stages of the disease. Affected individuals usually survive 8 to 10 years after the appearance of symptoms, but the course of the disease can range from 1 to 25 years. Death usually results from pneumonia, malnutrition, or general body wasting. [from Genetics Home Reference, Alzheimer disease; 2016.01.08]

(FlyBase Curators, 2013-)

Alzheimer disease can be classified as early-onset or late-onset. The signs and symptoms of the early-onset form appear before age 65, while the late-onset form appears after age 65. The early-onset form is much less common than the late-onset form, accounting for less than 5 percent of all cases of Alzheimer disease. [from Genetics Home Reference, Alzheimer disease; 2016.01.08]

(FlyBase Curators, 2013-)
Specific Disease Summary: Alzheimer disease, susceptibility to (postulated), SNRPN-related
OMIM report
Human gene(s) implicated
Symptoms and phenotype
Genetics

Locus identified as showing significant association with susceptibility to Alzheimer disease in an analysis of two genome-wide association studies (GWAS).

(Shulman et al., 2014)
Cellular phenotype and pathology
Molecular information

The protein encoded by SNRPN is a component of a small nuclear ribonucleoprotein complex and belongs to the snRNP SMB/SMN family. The protein plays a role in pre-mRNA processing, possibly tissue-specific alternative splicing events. [from Gene Cards, SNRPN; 2016.06.02]

(FlyBase Curators, 2013-)
External links
Disease synonyms
Ortholog Information
Human gene(s) in FlyBase
    Human gene (HGNC)
    Symbol / Name
    SNRPN; small nuclear ribonucleoprotein polypeptide N
    D. melanogaster ortholog (based on DIOPT)
    Dmel\SmB
    (DIOPT, 2013-)
    Comments on ortholog(s)

    Many to one: 2 human to 1 Drosophila; the fly gene SmB is orthologous to SNRPN and SNRPB in human.

    Other mammalian ortholog(s) used
      D. melanogaster Gene Information (1)
      Dmel\SmB
      Gene Snapshot
      Small ribonucleoprotein particle protein SmB (SmB) encodes an RNA binding protein that forms a heterodimeric sub-complex with the product of SmD3. They function as part of the heteroheptameric ring complex Sm core, which is involved in the formation of spliceosomal small nuclear RNPs (U1, U2, U4 and U5), which together catalyze pre-mRNA splicing. [Date last reviewed: 2019-03-14]
      Molecular function (GO)
      Cellular component (GO)
      Gene Groups / Pathways
      Comments on ortholog(s)

      High-scoring ortholog of human genes SNRPN and SNRPB (1 Drosophila to 2 human). Dmel\SmB shares 56-58% identity and 66-67% similarity with the human genes.

      Orthologs and Alignments from DRSC
      DIOPT - DRSC Integrative Ortholog Prediction Tool - Click the link below to search for orthologs in Humans
      H. sapiens (Human)
      Other Genes Used: Viral, Bacterial, Synthetic (0)
        Summary of Physical Interactions (39 groups)
        SmB
        protein-protein
        Interacting group
        Assay
        References
        SmB - Deaf1
        two hybrid, anti tag coimmunoprecipitation, anti tag western blot
        (Tang et al., 2023, Hu et al., 2017.6.13)
        SmB - Hez
        two hybrid
        (Lanfranco et al., 2017)
        SmB - l(3)05822
        two hybrid
        (Hu et al., 2017.6.13)
        SmB - msk
        anti tag coimmunoprecipitation, western blot
        (Natalizio and Matera, 2013)
        SmB - PAN3
        two hybrid, anti tag coimmunoprecipitation, anti tag western blot
        (Tang et al., 2023, Hu et al., 2017.6.13)
        SmB - Sbat
        two hybrid
        (Lanfranco et al., 2017)
        SmB - Sf3b5
        anti tag coimmunoprecipitation, peptide massfingerprinting
        (Stegeman et al., 2016)
        SmB - sina
        two hybrid
        (Hu et al., 2017.6.13)
        SmB - SmD2
        anti tag coimmunoprecipitation, western blot
        (Xiong et al., 2015)
        SmB - Smn
        anti tag coimmunoprecipitation, western blot, Identification by mass spectrometry, anti tag western blot
        (Gray et al., 2018, Gonsalvez et al., 2006)
        SmB - snf
        anti tag coimmunoprecipitation, peptide massfingerprinting
        (Stegeman et al., 2016)
        SmB - Snup
        anti bait coimmunoprecipitation, western blot
        (Natalizio and Matera, 2013)
        SmB - Spt3
        anti tag coimmunoprecipitation, peptide massfingerprinting
        (Stegeman et al., 2016)
        SmB - Spt20
        anti tag coimmunoprecipitation, peptide massfingerprinting
        (Stegeman et al., 2016)
        SmB - stau
        anti tag coimmunoprecipitation, western blot
        (Gonsalvez et al., 2010)
        SmB - Ubx
        anti tag coimmunoprecipitation, anti tag western blot, proximity-dependent biotin identification, Identification by mass spectrometry
        (Carnesecchi et al., 2020)
        SmB - yps
        anti bait coimmunoprecipitation, western blot
        (Gonsalvez et al., 2010)
        RNA-protein
        Interacting group
        Assay
        References
        SmB - Arpc4
        anti bait coimmunoprecipitation, quantitative reverse transcription pcr
        (Lu et al., 2014)
        SmB - ATPsynF
        anti bait coimmunoprecipitation, quantitative reverse transcription pcr
        (Lu et al., 2014)
        SmB - CG3776
        anti bait coimmunoprecipitation, quantitative reverse transcription pcr
        (Lu et al., 2014)
        SmB - Ciz1
        anti bait coimmunoprecipitation, quantitative reverse transcription pcr
        (Lu et al., 2014)
        SmB - dj-1β
        anti bait coimmunoprecipitation, quantitative reverse transcription pcr
        (Lu et al., 2014)
        SmB - mir-33
        anti tag coimmunoprecipitation, primer specific pcr
        (Xiong et al., 2015)
        SmB - osk
        anti bait coimmunoprecipitation, quantitative reverse transcription pcr
        (Gonsalvez et al., 2010)
        SmB - scaRNA:ΨU2-55
        anti bait coimmunoprecipitation, quantitative reverse transcription pcr
        (Lu et al., 2014)
        SmB - snRNA:LU
        anti bait coimmunoprecipitation, quantitative reverse transcription pcr
        (Lu et al., 2014)
        SmB - snRNA:U1:21D
        anti bait coimmunoprecipitation, autoradiography, quantitative reverse transcription pcr, anti tag coimmunoprecipitation, northern blot
        (Lu et al., 2014, Gonsalvez et al., 2010, Rajendra et al., 2007)
        SmB - snRNA:U1:82Eb
        anti tag coimmunoprecipitation, northern blot, anti bait coimmunoprecipitation, autoradiography, quantitative reverse transcription pcr
        (Gonsalvez et al., 2010, Rajendra et al., 2007)
        SmB - snRNA:U1:95Ca
        anti tag coimmunoprecipitation, northern blot, anti bait coimmunoprecipitation, quantitative reverse transcription pcr, autoradiography
        (Gonsalvez et al., 2010, Rajendra et al., 2007)
        SmB - snRNA:U1:95Cb
        anti bait coimmunoprecipitation, autoradiography, anti tag coimmunoprecipitation, northern blot, quantitative reverse transcription pcr
        (Gonsalvez et al., 2010, Rajendra et al., 2007)
        SmB - snRNA:U1:95Cc
        anti tag coimmunoprecipitation, northern blot, anti bait coimmunoprecipitation, quantitative reverse transcription pcr, autoradiography
        (Gonsalvez et al., 2010, Rajendra et al., 2007)
        SmB - snRNA:U2:14B
        anti tag coimmunoprecipitation, northern blot
        (Rajendra et al., 2007)
        SmB - snRNA:U2:34ABa
        anti tag coimmunoprecipitation, northern blot
        (Rajendra et al., 2007)
        SmB - snRNA:U2:34ABb
        anti tag coimmunoprecipitation, northern blot
        (Rajendra et al., 2007)
        SmB - snRNA:U2:34ABc
        anti tag coimmunoprecipitation, northern blot
        (Rajendra et al., 2007)
        SmB - snRNA:U2:38ABa
        anti tag coimmunoprecipitation, northern blot
        (Rajendra et al., 2007)
        SmB - snRNA:U2:38ABb
        anti tag coimmunoprecipitation, northern blot
        (Rajendra et al., 2007)
        SmB - snRNA:U4:38AB
        anti tag coimmunoprecipitation, primer specific pcr
        (Xiong et al., 2015)
        SmB - snRNA:U7
        pull down, peptide massfingerprinting
        (Sabath et al., 2013)
        Alleles Reported to Model Human Disease (Disease Ontology) (4 alleles)
        SmB
        Models Based on Experimental Evidence ( 1 )
        Allele
        Disease
        Evidence
        References
        SmBMI07584-GFSTF.0
        model of  tauopathy
        CEA
        (Hsieh et al., 2019)
        Modifiers Based on Experimental Evidence ( 4 )
        Alleles Representing Disease-Implicated Variants
        Genetic Tools, Stocks and Reagents
        Sources of Stocks
        Contact lab of origin for a reagent not available from a public stock center.
        Bloomington Stock Center Disease Page
        Related mammalian, viral, bacterial, or synthetic transgenes
        Allele
        Transgene
        Publicly Available Stocks
        Selected Drosophila transgenes
        Allele
        Transgene
        Publicly Available Stocks
        SmBUASp.Venus
        P{UASp-VFP-SmB}
        RNAi constructs available
        Allele
        Transgene
        Publicly Available Stocks
        SmBGD11620
        P{GD11620}
        w1118; P{GD11620}v40587
        SmBHM05097
        P{TRiP.HM05097}
        y1 v1; P{TRiP.HM05097}attP2
        SmBKK102021
        P{KK102021}
        P{KK102021}VIE-260B
        SmBNIG.5352R
        P{NIG.5352R}
        P{NIG.5352R}3
        SmBHMC02939
        P{TRiP.HMC02939}
        y1 v1; P{TRiP.HMC02939}attP40
        SmBHMC05629
        P{TRiP.HMC05629}
        y1 sc* v1 sev21; P{TRiP.HMC05629}attP2
        Selected Drosophila classical alleles
        Allele
        Allele class
        Mutagen
        Publicly Available Stocks
        SmBMI07584-GFSTF.0
        phiC31 integrase
        References (5)