SRP-dependent cotranslational targeting in Drosophila melanogaster

The signal recognition particle (SRP) recognizes signal sequences and transmembrane segments as they emerge from the ribosome, slows elongation and delivers the ribosome-nascent chain complex to the SRP receptor on the endoplasmic reticulum membrane. SRP is a ribonucleoprotein built on the 7SL RNA. Its Alu domain (SRP9 and SRP14) arrests elongation, and its S domain (SRP19, SRP54, SRP68 and SRP72) binds the signal sequence through the methionine-rich domain of the GTPase SRP54. The receptor is a heterodimer of the GTPases SRalpha and SRbeta. GTP-dependent interaction of SRP54 with SRalpha transfers the nascent chain to the Sec61 translocon, and reciprocal GTP hydrolysis releases SRP from its receptor.

MODULE:dmel_srp_cotranslational_targetingDRAFTCONCRETEBiological Processmodules/dmel_srp_cotranslational_targeting.yaml

SRP-dependent cotranslational protein targeting to membraneGO:0006614

FB:FBgg0001281

FlyBase gene group SRP: Signal recognition particle

FlyBase release FB2026_03 groups 8 D. melanogaster genes as signal recognition particle (SRP); this module models that group.

FB:FBgg0001282

FlyBase gene group SRPR: Signal recognition particle receptor

FlyBase release FB2026_03 groups 2 D. melanogaster genes as signal recognition particle receptor (SRPR); this module models that group.

GO:0006614

SRP-dependent cotranslational protein targeting to membrane

GO term grounding the module as SRP-dependent cotranslational protein targeting to membrane.

Boundary. The module ends at handover to the translocon; Sec61 and its partners are a separate module (dmel_sec61_translocon). Drosophila has two 7SL RNA genes, modelled together as the RNA scaffold of SRP. Domain assignments follow the conserved mammalian SRP structure. FlyBase groups realized by this module: SRP (FBgg0001281), SRPR (FBgg0001282). Participants were generated from the FlyBase gene-group membership and mapped to UniProtKB by projects/FLYBASE_GENE_GROUPS/generate_modules.py from module_specs/dmel_srp_cotranslational_targeting.yaml. Genes without a usable UniProtKB entry are grounded to their FlyBase gene ids: 7SLRNA:CR32864, 7SLRNA:CR42652. None of the member genes has a gene review in this repository yet.

6Nodes

5Parts

0Variant Sets

0Variants

5Annotons

1Connections

Derived QC

Recommended-field compliance

100.0% recommended fields populated

All recommended fields populated.

Module deep research

✗ none found

No MODULE:dmel_srp_cotranslational_targeting deep-research report alongside the module YAML.

Leaf nodes lacking representative members

✓ every leaf node grounds to a representative protein.

Template conformance

✓ every declared conforms_to bundle matches its template motif.

Reaction chaining (advisory)

✓ every PRECEDES step chains, or its break is acknowledged via chaining_status.

srp → srp_receptor [NOT_CHECKED]

Function consistency and core coverage

0 gene-function check(s) reflected in core functions · 0 conflict(s) · 3 evidence or coverage gap(s) (3 comparison(s))

Retained noncore functions are reported separately; they do not require promotion to core functions. Support from representative genes does not establish conservation across the whole family. Missing reviews or identifiers leave a claim unverified.

Annoton	Participant	Function	Assessment
srp_s_domain_complex/srp54k	Srp54k UniProtKB:Q9V3D9 Complex Unit	GTPase activity GO:0003924	Review Missing No ai-review exists for this protein; its function and core-function coverage cannot yet be checked.
srp_receptor_complex/srpralpha	SrpRalpha UniProtKB:Q9U5L1 Complex Unit	GTPase activity GO:0003924	Review Missing No ai-review exists for this protein; its function and core-function coverage cannot yet be checked.
srp_receptor_complex/srprbeta	SrpRbeta UniProtKB:Q9VSN9 Complex Unit	GTPase activity GO:0003924	Review Missing No ai-review exists for this protein; its function and core-function coverage cannot yet be checked.

Gene-review completeness (0/8 grounded genes reviewed)

0 complete review(s) · 0 with deep research · 8 missing review · 0 reviewed but lacking deep research

Gene	Review	Complete	Deep research
Srp19 P49963	✗	—	—
SrpRalpha Q9U5L1	✗	—	—
Srp54k Q9V3D9	✗	—	—
Srp72 Q9VDK7	✗	—	—
Srp14 Q9VDL0	✗	—	—
Srp9 Q9VSC1	✗	—	—
SrpRbeta Q9VSN9	✗	—	—
Srp68 Q9VSS2	✗	—	—

Tree

SRP-dependent cotranslational targetingBiological Processdmel_srp_cotranslational_targeting

Parts
1. 1. signal sequence recognition
2. Signal recognition particleBiological Processsrp
  
  Parts
  1. 1. SRP RNA scaffold
  2. 7SL RNABiological Processsrp_7sl_rna
    
    Annotons
    
    7SLRNA:CR32864 7SL RNA Gene: 7SLRNA:CR32864
    
    7SLRNA:CR42652 7SL RNA Gene: 7SLRNA:CR42652
  3. 2. elongation arrest
  4. SRP Alu domain proteinsBiological Processsrp_alu_domain
    
    Annotons
    
    SRP Alu domain proteins Protein Complex: SRP Alu domain proteins
  5. 3. signal sequence binding and receptor interaction
  6. SRP S domain proteinsBiological Processsrp_s_domain
    
    Annotons
    
    SRP S domain proteins Protein Complex: SRP S domain proteins
3. 2. ER membrane docking of SRP
4. SRP receptorBiological Processsrp_receptor
  
  Annotons
  - SRP receptor Protein Complex: SRP receptor

Details

Context

Drosophila melanogasterNCBITaxon:7227

endoplasmic reticulum membraneGO:0005789

SRP-dependent cotranslational targetingBiological Processdmel_srp_cotranslational_targeting

SRP ribonucleoprotein and its ER receptor that target ribosome-nascent chain complexes to the Sec61 translocon.

SRP-dependent cotranslational protein targeting to membraneGO:0006614

Context

Drosophila melanogasterNCBITaxon:7227

endoplasmic reticulum membraneGO:0005789

Connections

srp -> srp_receptor Precedes

SRP carrying a ribosome-nascent chain complex docks on the SRP receptor at the ER membrane.

Part 1: signal sequence recognition

Signal recognition particleBiological Processsrp

signal recognition particle, endoplasmic reticulum targetingGO:0005786

Part 1: SRP RNA scaffold

7SL RNABiological Processsrp_7sl_rna

Annotons

7SLRNA:CR32864 7SL RNA

srp_7sl_rna_7slrna_cr32864

Participant: Gene: 7SLRNA:CR32864

Gene:

7SLRNA:CR32864FB:FBgn0000003

7SLRNA:CR42652 7SL RNA

srp_7sl_rna_7slrna_cr42652

Participant: Gene: 7SLRNA:CR42652

Gene:

7SLRNA:CR42652FB:FBgn0261504

Part 2: elongation arrest

SRP Alu domain proteinsBiological Processsrp_alu_domain

Annotons

SRP Alu domain proteins

srp_alu_domain_complex

Participant: Protein Complex: SRP Alu domain proteins

Protein Complex:

SRP Alu domain proteins

Active units:

Srp9

Participant: Gene Product: Srp9

Gene Product:

Srp9UniProtKB:Q9VSC1

Srp14

Participant: Gene Product: Srp14

Gene Product:

Srp14UniProtKB:Q9VDL0

Part 3: signal sequence binding and receptor interaction

SRP S domain proteinsBiological Processsrp_s_domain

Annotons

SRP S domain proteins

srp_s_domain_complex

Participant: Protein Complex: SRP S domain proteins

Protein Complex:

SRP S domain proteins

Active units:

Srp19

Participant: Gene Product: Srp19

Gene Product:

Srp19UniProtKB:P49963

Srp54k

Participant: Gene Product: Srp54k

Gene Product:

Srp54kUniProtKB:Q9V3D9

Function:

GTPase activityGO:0003924

Srp68

Participant: Gene Product: Srp68

Gene Product:

Srp68UniProtKB:Q9VSS2

Srp72

Participant: Gene Product: Srp72

Gene Product:

Srp72UniProtKB:Q9VDK7

Part 2: ER membrane docking of SRP

SRP receptorBiological Processsrp_receptor

Annotons

SRP receptor

srp_receptor_complex

Participant: Protein Complex: SRP receptor

Protein Complex:

SRP receptorGO:0005785

Active units:

SrpRalpha

Participant: Gene Product: SrpRalpha

Gene Product:

SrpRalphaUniProtKB:Q9U5L1

Function:

GTPase activityGO:0003924

SrpRbeta

Participant: Gene Product: SrpRbeta

Gene Product:

SrpRbetaUniProtKB:Q9VSN9

Function:

GTPase activityGO:0003924