FB2025_05 , released December 11, 2025
Physical Interaction report
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General Information
Interaction Type
Interacting Genes
FlyBase ID
FBig0000097491
Interaction Network
Interactions Browser links
Pbp49 network
Pbp45 network
Reported Interactions
FBrf0100643-1.CH.MW
Description
physical association
Collection
Cell line used
Participants
Corresponds to
Reported as
Role
Note

PBP 45

neutral component

PBP 45

neutral component

PBP 45

neutral component

PBP 49

neutral component

PBP 49

neutral component

PBP 49

neutral component
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 embryonic nuclear extract of wild-type fly line; bait produced from endogenous gene; prey produced from endogenous gene.

The SNAP/PBP complex was isolated from soluble nuclear extract by fractionation on DEAE-cellulose and heparin columns.

DNA-binding subunits within the SNAP/PBP complex were detected by photo-cross-linking and molecular weight estimation of proteins on a gel. The identity of these proteins was later determined by using antibodies and supershift assays in a subsequent study (FBrf0174956).

FBrf0174956-1.EMSA.A
Reference
Description
physical association
Collection
Source/Stage
Cell line used
Participants
Corresponds to
Reported as
Role
Note

DmSNAP43

bait

V5, His tag

DmSNAP50

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

Pbp45, Pbp49 and Pbp95 are part of the SNAP (small nuclear RNA activating protein) complex, also known as the PBP (PSE binding protein) complex, involved in snRNA transcription.

Interaction in vitro; bait produced as recombinant fusion protein in transfected S2 cell extract; prey produced from endogenous gene.

Pbp45-containing complexes were affinity purified from transfected S2 cell extracts and used in electromobility shift assays using [32]P labeled DNA containing the U1 snRNA \'PSEA\' motif. The presence of other proteins in the Pbp45-DNA complex was assessed using antibodies to supershift the apparent migration of the protein:DNA complex.

FBrf0174956-3.EMSA.A
Reference
Description
physical association
Collection
Source/Stage
Cell line used
Participants
Corresponds to
Reported as
Role
Note

DmSNAP50

bait

V5, His tag

DmSNAP43

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

Pbp45, Pbp49 and Pbp95 are part of the SNAP (small nuclear RNA activating protein) complex, also known as the PBP (PSE binding protein) complex, involved in snRNA transcription.

Interaction in vitro; bait produced as recombinant fusion protein in transfected S2 cell extract; prey produced from endogenous gene.

Pbp49-containing complexes were affinity purified from transfected S2 cell extracts and used in electromobility shift assays using [32]P labeled DNA containing the U1 snRNA \'PSEA\' motif. The presence of other proteins in the Pbp49-DNA complex was assessed using antibodies to supershift the apparent migration of the protein:DNA complex.

FBrf0206207-3.CH.MW
Reference
Description
physical association
Collection
Source/Stage
Cell line used
Participants
Corresponds to
Reported as
Role
Note

SNAP50

neutral component

SNAP50

neutral component

SNAP50

neutral component

SNAP43

neutral component

SNAP43

neutral component

SNAP43

neutral component
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

The SNAP complex (Pbp45, Pbp49 AND Pbp95) has apparent molecular mass of 372 kDa.

Interaction in vitro; proteins produced as a recombinant fusion proteins in bacterial system.

FBrf0208672-4.coIP.WB
Description
physical association
Collection
Source/Stage
Cell line used
Participants
Corresponds to
Reported as
Role
Note

DmSNAP50

bait

FLAG tag

DmSNAP43

prey
Experimental entities
Corresponds to
Identifier
Reported
Role
Note
Subregions with role in interaction
Corresponds to
Description
Role
Coordinates
Note
SNAP finger domain
sufficient binding region
aa 292-376
interaction domain
sufficient binding region
aa 2-291
interaction domain
necessary binding region
aa 110-291
Isoform-specific participants
Corresponds to
Description
Role
Note
Comments concerning this interaction

Source was cell extract of S2 cell line; bait produced from transfected construct; prey produced from transfected construct.

Pbp95 is coexpressed with Pbp45 and Pbp49.

FBrf0208672-6.coIP.WB
Description
physical association
Collection
Source/Stage
Cell line used
Participants
Corresponds to
Reported as
Role
Note

DmSNAP43

bait

FLAG tag

DmSNAP50

prey
Experimental entities
Corresponds to
Identifier
Reported
Role
Note
Subregions with role in interaction
Corresponds to
Description
Role
Coordinates
Note
interaction domain
sufficient binding region
aa 2-172
interaction domain
necessary binding region
aa 1-67
Isoform-specific participants
Corresponds to
Description
Role
Note
Comments concerning this interaction

Source was cell extract of S2 cell line; bait produced from transfected construct; prey produced from transfected construct.

Pbp95 is coexpressed with Pbp45 and Pbp49.

FBrf0217869-1.CH.WB
Description
physical association
Collection
Source/Stage
Cell line used
Participants
Corresponds to
Reported as
Role
Note

Pbp45

bait

His and FLAG tag

Pbp49

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 cell extract of S2 cell line; bait produced from transfected construct; prey produced from transfected construct.

Pbp45, Pbp49, Pbp95 form trimeric complex. Captured as pairwise interactions.

External Crossreferences and Linkouts ( 1 )
Linkouts
MIST - An integrated Molecular Interaction Database
References (5)