FB2026_03 , released September 17, 2026
Physical Interaction report
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General Information
Interaction Type
Interacting Genes
FlyBase ID
FBig0000103760
Interaction Network
Interactions Browser links
Nrx-1 network
Spn network
Reported Interactions
FBrf0229911-1.coIP.WB
Description
physical association
Collection
Source/Stage
Cell line used
Participants
Corresponds to
Reported as
Role
Note

Nrx-1

bait
Spn 

Spn

prey
Experimental entities
Corresponds to
Identifier
Reported
Role
Note
Subregions with role in interaction
Corresponds to
Description
Role
Coordinates
Note
Isoform-specific participants
Corresponds to
Description
Role
Note
Comments concerning this interaction

Source was adult heads of wild-type fly line; bait produced from endogenous gene; prey produced from endogenous gene.

FBrf0229911-2.Y2H
Description
physical association
Assay
Collection
Source/Stage
Cell line used
Participants
Corresponds to
Reported as
Role
Note

Nrx-1

bait

fused to LexA DNA-binding domain

Spn 

Spn

prey

fused to GAL4 activation domain

Spn 
Spn 
Experimental entities
Corresponds to
Identifier
Reported
Role
Note
Subregions with role in interaction
Corresponds to
Description
Role
Coordinates
Note
C-terminal region
sufficient binding region
NGDRGYKTESEKAAAYGSHNPNAALLGNTSTNGSYHQQRQHHMHGGGGGGGAGQQQHHAQQQMHNGHNGNGNGGGGGGGGMMSSGSGSLGYGSDGRPQMAGLVQPKAKKRDSKDVKEWYV
PDZ binding motif
necessary binding region
KEWYV

"C-term*" construct

Spn 
central region
sufficient binding region
REELENGYDLHEKHSDLNQTYITGGESLHESIVSVESTQSDATLNQTTTIDDSIISSKHNSTYSLADAEQATSSTVLSTGVTELDDSQYYIPEYPPVRSKEVLVEAGVHYFEDGNFWMEVPGLLDFDDDDCSYPPITVRKNPKVRFSSGPIHVYSTFSVNDYDRRNEDVDPVAASAEYELEKRVEKMHVFPVELMKGPEGLGLSIIGMGVGADAGLEKLGIFVKTITDNGAAARDGRIQVNDQIIEVDGKSLVGVTQAYAASVLRNTSGLVKFQIGRERDPENSEVAQLIRLSLQADREKEERLKRQQEEYLRRTLDYSEDSTQPVSANSSVCEGPSSPVQVEHPMEVEATHSQEVESLKRLLQESEMGCLVKEEIIQNLKRKLVKLETTGNENELLSERLRQSERELGNIRKEAANLQNMLQQSQGQYMALDKKYNKAKRLVREYQQRELDMCHREEFYQQLLQEKDTEYNALVKKLKDRVINLEHELQETQRKAGFPVGLPYDSATLKLTPQMMRKT

"F3" construct

Spn 
PDZ domain residue K1259
mutation disrupting interaction
aa 1259

K1259A, "PDZ*" construct, coordinates corresponding to Spn-PG

Isoform-specific participants
Corresponds to
Description
Role
Note
Comments concerning this interaction

Source was yeast cell line; bait produced as transgenic fusion protein; prey produced as transgenic fusion protein (prey was previously cloned reagent).

Two-hybrid system: yeast LexA-BD/GAL4-AD

FBrf0229911-4.XC
Description
physical association
Collection
Source/Stage
Cell line used
Participants
Corresponds to
Reported as
Role
Note
Spn 

Spn

neutral component
Spn 

Spn

neutral component
Spn 
Spn 

Spn

neutral component
Spn 

Nrx-1

neutral component

Nrx-1

neutral component

Nrx-1

neutral component
Experimental entities
Corresponds to
Identifier
Reported
Role
Note
Subregions with role in interaction
Corresponds to
Description
Role
Coordinates
Note
Spn 
PDZ domain
sufficient binding region
HVFPVELMKGPEGLGLSIIGMGVGADAGLEKLGIFVKTITDNGAAARDGRIQVNDQIIEVDGKSLVGVTQAYAASVLRNTSGLVKFQIGR
PDZ binding motif
sufficient binding region
DSKDVKEWYV
Isoform-specific participants
Corresponds to
Description
Role
Note
Comments concerning this interaction

Interaction in vitro; Spn produced as a recombinant fusion protein in bacterial system; Nrx-1 peptide chemically synthesized.

FBrf0229911-6.ITC
Description
physical association
Collection
Source/Stage
Cell line used
Participants
Corresponds to
Reported as
Role
Note

Nrx-1

bait
Spn 

Spn

prey

MBP tag

Spn 
Experimental entities
Corresponds to
Identifier
Reported
Role
Note
Subregions with role in interaction
Corresponds to
Description
Role
Coordinates
Note
Spn 
PDZ domain
sufficient binding region
HVFPVELMKGPEGLGLSIIGMGVGADAGLEKLGIFVKTITDNGAAARDGRIQVNDQIIEVDGKSLVGVTQAYAASVLRNTSGLVKFQIGR
PDZ binding motif
sufficient binding region
DSKDVKEWYV
Isoform-specific participants
Corresponds to
Description
Role
Note
Comments concerning this interaction

Interaction in vitro; bait chemically synthesized; prey produced as a recombinant fusion protein in bacterial system.

The Spn PDZ domain binds the Nrx-1 PDZ binding motif peptide with Kd = 50uM (ten-fold lower affinity than interaction of the RhoGAP100F PDZ domain with the Nrx-1 peptide).

FBrf0229911-7.PD.MW
Description
physical association
Collection
Source/Stage
Cell line used
Participants
Corresponds to
Reported as
Role
Note
Spn 

Spn

bait

MBP tag

Spn 

Nrx-1

prey

GST tag

Experimental entities
Corresponds to
Identifier
Reported
Role
Note
Subregions with role in interaction
Corresponds to
Description
Role
Coordinates
Note
Spn 
PDZ domain
sufficient binding region
HVFPVELMKGPEGLGLSIIGMGVGADAGLEKLGIFVKTITDNGAAARDGRIQVNDQIIEVDGKSLVGVTQAYAASVLRNTSGLVKFQIGR
PDZ binding motif
sufficient binding region
DSKDVKEWYV
Isoform-specific participants
Corresponds to
Description
Role
Note
Comments concerning this interaction

Interaction in vitro; bait produced as a recombinant fusion protein in bacterial system; prey produced as a recombinant fusion protein in bacterial system.

External Crossreferences and Linkouts ( 1 )
Linkouts
MIST - An integrated Molecular Interaction Database
References (1)