Existing Annotations Review

GO Term	Evidence	Action	Reason
GO:0006614 SRP-dependent cotranslational protein targeting to membrane	IBA GO_REF:0000033	ACCEPT	Summary: Phylogenetic annotation of SRP9's defining biological process. As part of SRP, SRP9 (via the Alu/elongation-arrest domain) contributes to SRP-dependent co-translational targeting of proteins to the ER membrane. Conserved across the SRP9 family. Reason: Core biological process; SRP9 is an SRP subunit essential to co-translational ER targeting. Supporting Evidence: file:human/SRP9/SRP9-uniprot.txt mediates the cotranslational targeting
GO:0005786 signal recognition particle, endoplasmic reticulum targeting	IBA GO_REF:0000033	ACCEPT	Summary: Phylogenetic annotation of SRP9 as a constitutive subunit of the signal recognition particle. Conserved and directly established. Reason: Core cellular component; SRP9 is one of the six SRP protein subunits. Supporting Evidence: file:human/SRP9/SRP9-uniprot.txt consists of a 7SL RNA molecule of 300 nucleotides and six protein
GO:0005737 cytoplasm	IEA GO_REF:0000044	ACCEPT	Summary: Electronic transfer of the cytoplasmic localization from the UniProt subcellular location. SRP functions in the cytoplasm targeting nascent chains to the ER. Reason: Correct compartment; SRP acts in the cytoplasm. Supporting Evidence: file:human/SRP9/SRP9-uniprot.txt SUBCELLULAR LOCATION: Cytoplasm.
GO:0005829 cytosol	IEA GO_REF:0000117	ACCEPT	Summary: ARBA machine-learning electronic annotation of cytosolic localization, consistent with the cytoplasmic site of SRP function. Reason: Correct compartment; consistent with UniProt cytoplasm and Reactome cytosol. Supporting Evidence: file:human/SRP9/SRP9-uniprot.txt SUBCELLULAR LOCATION: Cytoplasm.
GO:0006614 SRP-dependent cotranslational protein targeting to membrane	IEA GO_REF:0000002	ACCEPT	Summary: InterPro-based electronic assignment of the core SRP-dependent co-translational targeting process. Reason: Correct core process; redundant with IBA/NAS evidence. Supporting Evidence: file:human/SRP9/SRP9-uniprot.txt mediates the cotranslational targeting
GO:0008312 7S RNA binding	IEA GO_REF:0000002	ACCEPT	Summary: InterPro-based annotation of SRP RNA (7S/7SL) binding. SRP9 binds the SRP 7SL RNA as part of the SRP9/SRP14 Alu-domain heterodimer; this RNA-binding is its core molecular function. Reason: Core molecular function; SRP9 (with SRP14) binds the Alu portion of the SRP RNA. Supporting Evidence: file:human/SRP9/SRP9-uniprot.txt The complex of SRP9 and SRP14 is required for SRP
GO:0045900 negative regulation of translational elongation	IEA GO_REF:0000002	ACCEPT	Summary: InterPro-based annotation of the elongation-arrest function. The SRP9/SRP14 Alu domain transiently arrests translation elongation by reaching into the ribosomal elongation-factor binding site. This is the defining SRP9-specific contribution to SRP function. Reason: Core biological process; SRP9 is part of the Alu/elongation-arrest domain that negatively regulates elongation. Supporting Evidence: PMID:34208095 SRP9 and SRP14 function in elongation arrest
GO:0048500 signal recognition particle	IEA GO_REF:0000002	ACCEPT	Summary: InterPro-based annotation of SRP complex membership (general SRP term). SRP9 is a constitutive subunit. Reason: Core cellular component; redundant with the more specific GO:0005786. Supporting Evidence: file:human/SRP9/SRP9-uniprot.txt Component of the signal recognition particle (SRP) complex
GO:0005515 protein binding	IPI PMID:25910212 Widespread macromolecular interaction perturbations in human...	KEEP AS NON CORE	Summary: High-throughput interactome screen; the captured partner (ACTN2) is unrelated to SRP9's function. Bare protein binding is uninformative. Reason: Incidental high-throughput interaction; bare protein binding is uninformative. Supporting Evidence: file:human/SRP9/SRP9-uniprot.txt P49458; P35609: ACTN2
GO:0005515 protein binding	IPI PMID:28514442 Architecture of the human interactome defines protein commun...	KEEP AS NON CORE	Summary: Human interactome study capturing the functionally central SRP9-SRP14 (P37108) Alu-heterodimer interaction. Biologically meaningful but the bare protein binding term is uninformative. Reason: Records the real SRP14 heterodimer interaction, but bare protein binding is uninformative; the informative MF is captured by GO:0008312 and complex membership by GO:0005786. Supporting Evidence: file:human/SRP9/SRP9-uniprot.txt P49458; P37108: SRP14
GO:0005515 protein binding	IPI PMID:30021884 Histone Interaction Landscapes Visualized by Crosslinking Ma...	KEEP AS NON CORE	Summary: Crosslinking-MS interactome capturing the SRP9-SRP14 (P37108) interaction. Bare protein binding is uninformative. Reason: Records the real SRP14 interaction; bare protein binding is uninformative. Supporting Evidence: file:human/SRP9/SRP9-uniprot.txt P49458; P37108: SRP14
GO:0005515 protein binding	IPI PMID:32296183 A reference map of the human binary protein interactome.	KEEP AS NON CORE	Summary: HuRI binary interactome capturing the SRP9-SRP14 (P37108) interaction. Bare protein binding is uninformative. Reason: Records the real SRP14 interaction; bare protein binding is uninformative. Supporting Evidence: file:human/SRP9/SRP9-uniprot.txt P49458; P37108: SRP14
GO:0005515 protein binding	IPI PMID:32814053 Interactome Mapping Provides a Network of Neurodegenerative ...	KEEP AS NON CORE	Summary: Neurodegenerative-disease interactome mapping; captured partners (CDHR3, DPP9, RYBP) are unrelated to SRP9's function. Bare protein binding is uninformative. Reason: Incidental high-throughput interactions; bare protein binding is uninformative. Supporting Evidence: file:human/SRP9/SRP9-uniprot.txt P49458; Q6ZTQ4: CDHR3
GO:0005515 protein binding	IPI PMID:33961781 Dual proteome-scale networks reveal cell-specific remodeling...	KEEP AS NON CORE	Summary: Proteome-scale interactome capturing the SRP9-SRP14 (P37108) interaction. Bare protein binding is uninformative. Reason: Records the real SRP14 interaction; bare protein binding is uninformative. Supporting Evidence: file:human/SRP9/SRP9-uniprot.txt P49458; P37108: SRP14
GO:0005515 protein binding	IPI PMID:35271311 OpenCell: Endogenous tagging for the cartography of human ce...	KEEP AS NON CORE	Summary: OpenCell endogenous-tagging interactome capturing the SRP9-SRP14 (P37108) interaction. Bare protein binding is uninformative. Reason: Records the real SRP14 interaction; bare protein binding is uninformative. Supporting Evidence: file:human/SRP9/SRP9-uniprot.txt P49458; P37108: SRP14
GO:0005515 protein binding	IPI PMID:40205054 Multimodal cell maps as a foundation for structural and func...	KEEP AS NON CORE	Summary: Multimodal cell map capturing the SRP9-SRP14 (P37108) interaction. Bare protein binding is uninformative. Reason: Records the real SRP14 interaction; bare protein binding is uninformative. Supporting Evidence: file:human/SRP9/SRP9-uniprot.txt P49458; P37108: SRP14
GO:0005786 signal recognition particle, endoplasmic reticulum targeting	NAS PMID:34208095 SRPassing Co-translational Targeting: The Role of the Signal...	ACCEPT	Summary: ComplexPortal NAS assertion of SRP complex membership, from the SRP review describing the SRP9/SRP14 Alu domain. Reason: Core cellular component; SRP9 is an SRP subunit. Supporting Evidence: PMID:34208095 Alu domain
GO:0006617 SRP-dependent cotranslational protein targeting to membrane, signal sequence recognition	NAS PMID:34208095 SRPassing Co-translational Targeting: The Role of the Signal...	KEEP AS NON CORE	Summary: ComplexPortal NAS (complex-level) annotation of signal-sequence recognition. Signal-sequence recognition is performed by the SRP54 subunit of the SRP, not directly by SRP9, whose specific role is elongation arrest within the Alu domain. The term applies at the SRP complex level of which SRP9 is part. Reason: Complex-level NAS annotation; signal-sequence recognition is the SRP54 function, while SRP9's direct contribution is elongation arrest. Supporting Evidence: PMID:34208095 signal sequence
GO:0005515 protein binding	IPI PMID:24965446 Host factors that interact with the pestivirus N-terminal pr...	KEEP AS NON CORE	Summary: SRP9 co-purifies with the pestivirus Npro ribonucleoprotein complex; an incidental ribosomal/RNP capture from a viral interactome study. Bare protein binding is uninformative. Reason: Incidental viral RNP co-purification; bare protein binding is uninformative. Supporting Evidence: PMID:24965446 components of the ribonucleoprotein complex
GO:0005829 cytosol	TAS Reactome:R-HSA-1799332	ACCEPT	Summary: Reactome curation of cytosolic localization, consistent with SRP's cytoplasmic site of action. Reason: Correct compartment; redundant with UniProt cytoplasm. Supporting Evidence: file:human/SRP9/SRP9-uniprot.txt SUBCELLULAR LOCATION: Cytoplasm.
GO:0005786 signal recognition particle, endoplasmic reticulum targeting	NAS PMID:17154533 Compartmentalization directs assembly of the signal recognit...	ACCEPT	Summary: NAS assertion of SRP complex membership from a study on compartmentalized SRP assembly. Reason: Core cellular component; SRP9 is an SRP subunit. Supporting Evidence: PMID:17154533 Compartmentalization directs assembly of the signal recognition particle
GO:0003723 RNA binding	TAS PMID:7730321 Human signal recognition particle (SRP) Alu-associated prote...	ACCEPT	Summary: SRP9 (with SRP14) is the Alu RNA-binding protein that binds the Alu region of 7SL RNA. RNA binding is correct but is the general parent of the more specific 7S RNA binding. Reason: Correct molecular function; the more specific GO:0008312 (7S RNA binding) better captures SRP9's role. Supporting Evidence: PMID:7730321 regulates translational elongation of
GO:0005047 signal recognition particle binding	TAS PMID:7730321 Human signal recognition particle (SRP) Alu-associated prote...	KEEP AS NON CORE	Summary: Annotation of SRP9 binding the signal recognition particle. SRP9 is itself a constitutive subunit of SRP rather than an external SRP-binding factor, so this is redundant with its part_of SRP membership. Reason: SRP9 is part of SRP (captured by GO:0005786); describing it as SRP-binding is redundant and not the informative core MF. Supporting Evidence: file:human/SRP9/SRP9-uniprot.txt consists of a 7SL RNA molecule of 300 nucleotides and six protein
GO:0005785 signal recognition particle receptor complex	TAS PMID:7730321 Human signal recognition particle (SRP) Alu-associated prote...	MARK AS OVER ANNOTATED	Summary: SRP9 is annotated as part of the signal recognition particle receptor (SR) complex. This is incorrect; PMID:7730321 characterizes SRP9 as a component of the SRP (the Alu RNA-binding protein), not of the SRP receptor (SRalpha/SRbeta) complex. This appears to be an SRP-versus-SRP-receptor curation confusion. Reason: SRP9 is a subunit of SRP, not of the SRP receptor complex; the cited paper concerns SRP9 within SRP, so this CC is a mis-/over-annotation. Supporting Evidence: PMID:7730321 regulates translational elongation of

Core Functions

RNA-binding subunit that, as an obligate heterodimer with SRP14, binds the Alu portion of the SRP 7SL RNA to form the Alu (elongation-arrest) domain of the signal recognition particle.

Molecular Function:

7S RNA binding

In Complex:

signal recognition particle, endoplasmic reticulum targeting

Supporting Evidence:

file:human/SRP9/SRP9-uniprot.txt
The complex of SRP9 and SRP14 is required for SRP
PMID:34208095
SRP9 and SRP14 function in elongation arrest
PMID:26585389
We defined a minimal Alu RNA sufficient for effective retrotransposition and determined a high-resolution structure of its complex with the SRP9/14 proteins.

Part of the SRP Alu domain that transiently arrests translation elongation at the ribosomal elongation-factor site, pausing the nascent chain while SRP-dependent co-translational targeting delivers the ribosome to the ER membrane.

Molecular Function:

7S RNA binding

Directly Involved In:

negative regulation of translational elongation SRP-dependent cotranslational protein targeting to membrane

In Complex:

signal recognition particle, endoplasmic reticulum targeting

Supporting Evidence:

PMID:34208095
SRP9 and SRP14 function in elongation arrest
PMID:26585389
The RNA adopts a compact, closed conformation that matches the envelope of the SRP Alu domain in the ribosomal translation elongation factor-binding site.

References

GO_REF:0000002

Gene Ontology annotation through association of InterPro records with GO terms

GO_REF:0000033

Annotation inferences using phylogenetic trees

GO_REF:0000044

Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location vocabulary mapping

GO_REF:0000117

Electronic Gene Ontology annotations created by ARBA machine learning models

PMID:7730321

Human signal recognition particle (SRP) Alu-associated protein also binds Alu interspersed repeat sequence RNAs. Characterization of human SRP9.

SRP9 with SRP14 (SRP9/14) is the Alu RNA-binding protein that binds the Alu region of 7SL RNA and regulates translational elongation of ribosomes engaged by SRP.

PMID:17154533

Compartmentalization directs assembly of the signal recognition particle.

Describes compartmentalized (nucleolar/cytoplasmic) assembly of SRP, of which SRP9 is a subunit.

PMID:24965446

Host factors that interact with the pestivirus N-terminal protease, Npro, are components of the ribonucleoprotein complex.

PMID:25910212

Widespread macromolecular interaction perturbations in human genetic disorders.

PMID:28514442

Architecture of the human interactome defines protein communities and disease networks.

PMID:30021884

Histone Interaction Landscapes Visualized by Crosslinking Mass Spectrometry in Intact Cell Nuclei.

PMID:32296183

A reference map of the human binary protein interactome.

PMID:32814053

Interactome Mapping Provides a Network of Neurodegenerative Disease Proteins and Uncovers Widespread Protein Aggregation in Affected Brains.

PMID:33961781

Dual proteome-scale networks reveal cell-specific remodeling of the human interactome.

PMID:34208095

SRPassing Co-translational Targeting: The Role of the Signal Recognition Particle in Protein Targeting and mRNA Protection.

SRP9 and SRP14 form the Alu domain of SRP and function in elongation arrest, positioning near the ribosomal elongation-factor binding site to pause translation; signal-sequence recognition is performed by SRP54.

PMID:35271311

OpenCell: Endogenous tagging for the cartography of human cellular organization.

PMID:40205054

Multimodal cell maps as a foundation for structural and functional genomics.

Reactome:R-HSA-1799332

Reactome: Nascent polypeptide:mRNA:ribosome complex binds signal recognition particle (SRP)

PMID:26585389

Retrotransposition and Crystal Structure of an Alu RNP in the Ribosome-Stalling Conformation.

2.0 A crystal structure of the human Alu RNP (SRP9/14 bound to Alu RNA) in the ribosome-stalling conformation; SRP9/14 clamps the Alu RNA and docks at the ribosomal elongation-factor binding site, and mutations weakening the SRP9/14-RNA interface abolish Alu retrotransposition.

PMID:37156570

Nuclear SRP9/SRP14 heterodimer transcriptionally regulates 7SL and BC200 RNA expression.

SRP9/14 localizes substantially in the nucleus; siRNA knockdown selectively reduces the Alu-like Pol III transcripts 7SL (RN7SL1) and BC200 (BCYRN1) by decreasing Pol III occupancy at these loci rather than altering RNA stability, defining a noncanonical nuclear transcriptional role for SRP9/14.

PMID:37309897

Alu RNA fold links splicing with signal recognition particle proteins.

SRP9/14 binds compact (closed) Alu RNA conformations and modulates inclusion of Alu-derived exons, with RNA structure (closed vs open Alu fold) predicting exon inclusion; demonstrates a noncanonical SRP9/14 role in pre-mRNA splicing regulation.

PMID:38858088

The nucleolar phase of signal recognition particle assembly.

SRP proteins (including SRP9/14) associate with many nucleolar and ribosome-biogenesis factors; GFP-SRP9 appears mostly nuclear with faint cytoplasmic staining, and nucleolar integrity is required for proper SRP protein localization, supporting a nucleolar phase of SRP assembly.

PMID:39563162

The role of SRP9/SRP14 in regulating Alu RNA.

Reviews SRP9/14 regulation of Alu-family RNAs (maturation, trafficking, splicing, retrotransposition, transcription); primate SRP9/14 is present at ~20-fold molar excess over assembled SRP and binds 7SL with sub-nanomolar affinity, enabling extensive extra-canonical Alu-RNA regulation.

PMID:38847231

Significance of signal recognition particle 9 nuclear translocation: implications for pancreatic cancer prognosis and functionality.

In resected pancreatic cancer, higher SRP9 nuclear staining is associated with improved recurrence-free survival; SRP9 nuclear translocation is modulated by amino-acid/nutrient status.

file:human/SRP9/SRP9-uniprot.txt

UniProt entry P49458 (SRP9_HUMAN), Signal recognition particle 9 kDa protein

SRP9 is a subunit of the SRP ribonucleoprotein (7SL RNA + six proteins); with SRP14 and the Alu portion of the SRP RNA it forms the elongation-arrest domain; binds RNA as the SRP9/SRP14 heterodimer; cytoplasmic.

Suggested Experiments

Experiment: Reconstitute SRP with wild-type versus RNA-binding-deficient SRP9 to quantify the contribution of the SRP9/SRP14 Alu domain to elongation arrest and targeting efficiency on defined nascent-chain substrates.

Experiment: Use selective ribosome profiling in cells depleted of SRP9 to measure genome-wide effects on co-translational ER targeting and elongation pausing of signal-sequence-bearing mRNAs.

Deep Research

Falcon

(SRP9-deep-research-falcon.md)

this with annotations you find in gene/protein databases, but these can be outdated or inaccurate. Falcon Edison Scientific Literature 59 citations 2 artifacts 2026-06-12T02:56:28.930682

Edison artifact artifact-00 (text/markdown)

## Context ID: pqac-00000047 The requested structural information is displayed in Figures 2 and 3 of the document. Figure 2A provides the high-resolution crysta (image/png)

The research report should be a detailed narrative explaining the function, biological processes, and localization of the gene product. Citations should be given for all claims.

You should prioritize authoritative reviews and primary scientific literature when conducting research. You can supplement
this with annotations you find in gene/protein databases, but these can be outdated or inaccurate.

We are specifically interested in the primary function of the gene - for enzymes, what reaction is catalyzed, and what is the substrate specificity? For transporters, what is the substrate? For structural proteins or adapters, what is the broader structural role? For signaling molecules, what is the role in the pathway.

We are interested in where in or outside the cell the gene product carries out its function.

We are also interested in the signaling or biochemical pathways in which the gene functions. We are less interested in broad pleiotropic effects, except where these elucidate the precise role.

Include evidence where possible. We are interested in both experimental evidence as well as inference from structure, evolution, or bioinformatic analysis. Precise studies should be prioritized over high-throughput, where available.

Research Report: Human SRP9 (UniProt P49458)

1. Key concepts and definitions (current understanding)

Gene/protein identity and complex membership. Human SRP9 encodes the signal recognition particle 9 kDa protein, which functions as an obligate heterodimer with SRP14 (SRP9/14) and binds the Alu domain of the SRP RNA (7SL/RN7SL1). This SRP9/14–RNA module is the Alu domain of mammalian SRP and is positioned at the ribosome factor-binding (GTPase) center where it modulates translation elongation during co-translational targeting. (faoro2021noncanonicalfunctionsand pages 3-4, kellogg2021srpassingcotranslationaltargeting pages 11-13, voorhees2015structuresofthe pages 7-9)

Canonical SRP pathway role. In mammalian SRP, SRP9/14 stabilizes a compact (“closed”) Alu RNA architecture that fits into the elongation-factor binding site of the ribosome and is mechanistically consistent with translation slowing/retardation to increase the time window for successful ER targeting. Structural reconstructions of scanning vs engaged SRP–ribosome complexes show Alu-domain density at the ribosomal GTPase center in both states, supporting a model in which SRP9/14 contributes to dynamic competition with elongation factors rather than being the primary determinant of SRP binding affinity. (voorhees2015structuresofthe pages 12-14, voorhees2015structuresofthe pages 14-15, wild2019reconstitutionofthe pages 1-2)

SRP9 as an RNA-binding structural protein rather than an enzyme. SRP9 does not catalyze a chemical reaction; its primary function is RNA binding and RNP architecture, acting as part of an RNA–protein clamp/chaperone that stabilizes specific RNA folds (7SL Alu domain and Alu-derived RNAs). High-resolution structural analysis of a human Alu RNP (SRP9/14 + Alu RNA) shows extensive protein–RNA interfaces consistent with this architectural role. (ahl2015retrotranspositionandcrystal pages 5-6, ahl2015retrotranspositionandcrystal pages 6-7)

2. Recent developments and latest research (prioritizing 2023–2024)

2.1 Nuclear SRP9/14 as a Pol III transcriptional regulator (2023)

A major update is the demonstration of a nuclear role for SRP9/14 in regulating Pol III transcripts.

In MCF-7 cells, SRP9/14 was reported to be heavily localized in the nucleus by immunofluorescence and subcellular fractionation, and siRNA knockdown of either SRP9 or SRP14 caused reduction of both proteins, consistent with mutual stabilization of the heterodimer. Knockdown produced selective decreases in Alu-like Pol III transcripts—notably 7SL (RN7SL1) and BC200 (BCYRN1)—with minimal effect on other Pol III RNAs (e.g., a tRNA control). Quantitatively, 7SL RNA decreased modestly by 48 h and more strongly by 72 h (~40% by RT-qPCR), whereas BC200 was dramatically reduced (>80% by 48 h and ~95% by 72 h). (Gussakovsky et al., RNA, May 2023, https://doi.org/10.1261/rna.079649.123) (gussakovsky2023nuclearsrp9srp14heterodimer pages 2-3, gussakovsky2023nuclearsrp9srp14heterodimer pages 3-5)

Mechanistically, this phenotype was attributed to transcriptional regulation, not altered RNA stability: measured half-lives were similar and short (7SL 1.7 h, 95% CI 1.4–2.1; BC200 1.5 h, 95% CI 1.3–1.6) and were not changed upon SRP9/14 depletion. In contrast, Pol III occupancy (ChIP-qPCR) decreased over time; for example, at the 7SL locus Pol III occupancy decreased ~15% at 48 h (P=1.3×10−2) and remained ~15% reduced at 72 h (P=6.5×10−5). At BC200, Pol III occupancy decreased progressively (15% at 24 h, P=6.8×10−3; 32% at 48 h, P=2.0×10−3; 48% at 72 h, P=1.9×10−4). (Gussakovsky et al., RNA, May 2023, https://doi.org/10.1261/rna.079649.123) (gussakovsky2023nuclearsrp9srp14heterodimer pages 5-7)

2.2 SRP9/14 in Alu-exon splicing regulation (2023)

Borovská et al. provided strong evidence that SRP9/14 functions beyond canonical SRP in splicing regulation of Alu-derived exons, where RNA structure (closed vs open Alu conformations) predicts exon inclusion better than sequence-motif heuristics. The authors combined structure-guided mutagenesis of an AluJ exon in the human F8 gene, biochemical probing/pull-down assays, and cellular RNAi experiments to show SRP9/14 binds specific Alu RNA conformations and modulates exon inclusion in a mutation-dependent manner. (Borovská et al., Nucleic Acids Research, Jun 2023, https://doi.org/10.1093/nar/gkad500) (borovska2023alurnafold pages 1-2, borovska2023alurnafold pages 9-11)

2.3 SRP biogenesis and nucleolar coordination (2024)

Issa et al. (2024) investigated SRP assembly and the nucleolar phase using quantitative interactome proteomics and imaging. They reported SRP proteins associate with many nucleolar and ribosome-biogenesis factors, identifying 95 newly identified nucleolar/ribosome-biogenesis-related SRP interactors (173 total SRP-associated nucleolar/ribosome biogenesis factors). Their localization experiments indicated GFP-SRP9 appeared mostly nuclear with faint cytoplasmic staining and that GFP-SRP9/SRP14 heterodimers can stall in assembly intermediates, supporting the idea that nucleolar integrity is required for proper localization and that SRP assembly may involve additional compartments such as Cajal bodies. (Issa et al., Life Science Alliance, Jun 2024, https://doi.org/10.26508/lsa.202402614) (issa2024thenucleolarphase pages 9-10, issa2024thenucleolarphase pages 3-5)

2.4 Updated synthesis of SRP9/14 regulation of Alu RNAs (2024 review)

A 2024 review emphasizes SRP9/14’s breadth of Alu RNA regulation, including Alu RNA maturation, trafficking, and functional diversification, and highlights quantitative constraints relevant to cellular competition between 7SL and other Alu-family transcripts: primate SRP9/14 is described as present in ~20-fold molar excess over assembled SRP, and binding to 7SL is described as sub-nanomolar. (Gussakovsky et al., RNA Biology, Nov 2024, https://doi.org/10.1080/15476286.2024.2430817) (gussakovsky2024theroleof pages 1-2, gussakovsky2024theroleof pages 2-4)

3. Current applications and real-world implementations

Clinical pathology / prognosis (pancreatic cancer). Sato et al. used immunohistochemistry on 38 resected pancreatic cancer cases (no preoperative therapy) and stratified tumors by SRP9 nuclear staining (>50% vs ≤50%). The >50% nuclear-staining group (n=24) showed significantly improved recurrence-free survival (P=0.037) compared with the ≤50% group (n=14), while overall survival did not differ significantly (P=0.604). Their cell-based work further linked SRP9 nuclear translocation to nutrient status (amino-acid deficiency suppressed nuclear translocation with P<0.0001 in quantified assays). (Sato et al., International Journal of Oncology, Jun 2024, https://doi.org/10.3892/ijo.2024.5662) (sato2024significanceofsignal pages 11-12, sato2024significanceofsignal pages 12-13, sato2024significanceofsignal pages 5-8)

Biotechnology relevance: retrotransposition and RNA–protein fold stabilization. Structural and functional work on SRP9/14-bound Alu RNPs provides a mechanistic framework for how Alu RNAs form retrotransposition-competent RNPs by co-opting SRP proteins, relevant to contexts where retroelement behavior is measured or engineered (e.g., retrotransposon-derived tools). (Ahl et al., Molecular Cell, Dec 2015, https://doi.org/10.1016/j.molcel.2015.10.003) (ahl2015retrotranspositionandcrystal pages 3-4, ahl2015retrotranspositionandcrystal pages 11-12)

4. Expert opinions and analysis (authoritative interpretations)

Translation slowdown as a kinetic facilitator rather than absolute arrest in mammals. Structural analyses argue for a kinetic model in which the Alu domain (SRP9/14) transiently occupies and is displaced from the GTPase center through the elongation cycle, yielding a modest slowdown that expands the targeting window; scanning-state SRP is more readily displaced by a translational GTPase surrogate, whereas engaged-state SRP is more stable. This reconciles Alu positioning with ongoing translation and emphasizes SRP9/14’s regulatory (not necessarily essential binding) contribution. (Voorhees & Hegde, eLife, Jul 2015, https://doi.org/10.7554/eLife.07975) (voorhees2015structuresofthe pages 12-14, voorhees2015structuresofthe pages 9-10, voorhees2015structuresofthe pages 14-15)

Domain contributions to ribosome binding and why SRP9/14 may be hard to quantify by affinity alone. Reconstitution and MST show SRP54 and SRP68/72 dominate measurable SRP–ribosome binding, while the Alu domain contributes little to affinity in those assays. This supports the interpretation that SRP9/14’s key role is geometric/steric regulation at the factor-binding site rather than driving high-affinity docking of SRP to ribosomes. (Wild et al., Nucleic Acids Research, Jan 2019, https://doi.org/10.1093/nar/gky1324) (wild2019reconstitutionofthe pages 10-11, wild2019reconstitutionofthe pages 5-5)

Noncanonical roles as a consequence of SRP9/14 abundance and shared structural motifs across Alu-family RNAs. Reviews highlight that the same structural motif enabling SRP9/14 binding to 7SL is shared with primate-specific Alu RNAs, implying that a large pool of SRP9/14 can regulate Alu-family transcripts in nucleus and cytoplasm (splicing, retrotransposition, translation regulation), especially given the reported ~20-fold molar excess over assembled SRP. (Faoro & Ataide, Frontiers in Molecular Biosciences, May 2021, https://doi.org/10.3389/fmolb.2021.679584; Gussakovsky et al., RNA Biology, Nov 2024, https://doi.org/10.1080/15476286.2024.2430817) (faoro2021noncanonicalfunctionsand pages 3-4, gussakovsky2024theroleof pages 1-2)

5. Relevant statistics and data highlights

Structural and energetic constraints on SRP9/14–Alu RNP function. The human Alu RNP crystal structure was solved at 2.0 Å; SRP9/14 binds with a total interface area ~1,820 Å² (SRP9 ~700 Å²; SRP14 ~1,120 Å²). Mutations weakening SRP9/14 interaction beyond ΔΔG > 3.5 kcal/mol abolished retrotransposition, providing a quantitative link between SRP9/14 binding energy and retroelement activity. (Ahl et al., 2015, https://doi.org/10.1016/j.molcel.2015.10.003) (ahl2015retrotranspositionandcrystal pages 5-6, ahl2015retrotranspositionandcrystal pages 9-11)

Human SRP–ribosome binding constants (domain-resolved). Reconstituted binding experiments indicate very tight binding of assembled SRP to ribosomes (sub-nanomolar in the assay configuration), with key determinants including SRP54 (KD ~30 nM for isolated SRP54) and SRP68/72 (KD ~160 ± 20 nM, Hill coefficient ~2.3). (Wild et al., 2019, https://doi.org/10.1093/nar/gky1324) (wild2019reconstitutionofthe pages 6-7, wild2019reconstitutionofthe pages 5-5)

Transcriptional regulation metrics (SRP9/14 knockdown). SRP9/14 depletion did not change measured RNA half-lives (7SL 1.7 h; BC200 1.5 h) but reduced Pol III occupancy at target loci with statistically significant P-values and caused marked time-dependent decreases in steady-state RNA, particularly BC200 (up to ~95% reduction by 72 h). (Gussakovsky et al., 2023, https://doi.org/10.1261/rna.079649.123) (gussakovsky2023nuclearsrp9srp14heterodimer pages 5-7, gussakovsky2023nuclearsrp9srp14heterodimer pages 2-3)

Clinical association statistics (pancreatic cancer). In a surgical cohort, SRP9 nuclear staining >50% was associated with improved recurrence-free survival (P=0.037), while proliferation (Ki-67) showed no trend (R²=0.007; P=0.622). (Sato et al., 2024, https://doi.org/10.3892/ijo.2024.5662) (sato2024significanceofsignal pages 11-12, sato2024significanceofsignal pages 12-13)

Functional-genomics disease associations (hypothesis-generating). Open Targets lists SRP9 associations with disease categories including neurodegenerative disease and osteoarthritis, with association scores (e.g., neurodegenerative disease score ~0.542) and evidence counts of 5 in the returned set; these represent aggregated functional-genomics evidence rather than direct clinical causality. (OpenTargets Search: -SRP9)

Visual evidence from primary literature

Structural placement of SRP9/14-bound Alu RNP at the ribosomal elongation factor-binding site and overlay with eEF2 are shown in cropped figures from Ahl et al. 2015. (ahl2015retrotranspositionandcrystal media 866dee84, ahl2015retrotranspositionandcrystal media c0bafdb5)

Summary

Human SRP9 (UniProt P49458) is best understood as an RNA-binding structural subunit of the SRP Alu domain that, through an obligate heterodimer with SRP14, stabilizes RNA conformations that interact with the ribosomal factor-binding center to slow translation and facilitate co-translational ER targeting. Quantitative binding studies suggest SRP9/14 is not the primary driver of SRP’s overall ribosome affinity, consistent with a regulatory/steric function. Recent 2023–2024 work substantially expands SRP9/14 biology to include nuclear roles in Pol III transcriptional control of 7SL and BC200, a mechanistic role in Alu exon splicing regulation, and potential clinical relevance via SRP9 nuclear localization patterns in pancreatic cancer prognosis.

Category	Key claim	Evidence type	Quantitative/statistical details	Primary source with year and DOI URL	Citation ID placeholder
Canonical SRP function	SRP9 forms an obligate SRP9/14 heterodimer that clamps the 5′ and 3′ ends of the Alu domain RNA, stabilizing the closed ribosome-stalling conformation required for translational slowdown during co-translational targeting.	Structure	Human Alu RNP crystal structure solved at 2.0 Å; SRP9 contributes ~700 Å² of protein-RNA interface within a total ~1,820 Å² SRP9/14-RNA interface; docking places the complex at the elongation factor-binding site.	Ahl et al., 2015, Molecular Cell. https://doi.org/10.1016/j.molcel.2015.10.003	(ahl2015retrotranspositionandcrystal pages 5-6, ahl2015retrotranspositionandcrystal pages 6-7, ahl2015retrotranspositionandcrystal pages 1-3)
Canonical SRP function	In mammalian scanning and engaged SRP-ribosome states, the SRP9/14-containing Alu domain sits at the ribosomal GTPase center, where it can compete with elongation factors and prolong the targeting window.	Cryo-EM structure/biochemical competition	Hbs1-DN displaced SRP from scanning ribosome-nascent chain complexes by up to ~70% but not from engaged complexes, supporting dynamic Alu competition at the factor-binding center.	Voorhees & Hegde, 2015, eLife. https://doi.org/10.7554/eLife.07975	(voorhees2015structuresofthe pages 6-7, voorhees2015structuresofthe pages 7-9, voorhees2015structuresofthe pages 9-10)
Canonical SRP function	SRP9/14 is not the dominant ribosome affinity determinant for human SRP; SRP54 and SRP68/72 account for most measurable binding, while the Alu domain contributes little or only slightly in reconstituted assays.	MST binding/reconstitution	Full SRP binds in the (sub-)nanomolar range; isolated SRP54 KD ~30 nM; SRP68/72 KD ~160 ± 20 nM with Hill coefficient ~2.3; SR heterodimer KD 410 ± 50 nM; Alu contribution not quantifiable or minor.	Wild et al., 2019, Nucleic Acids Research. https://doi.org/10.1093/nar/gky1324	(wild2019reconstitutionofthe pages 5-5, wild2019reconstitutionofthe pages 10-11, wild2019reconstitutionofthe pages 6-7, wild2019reconstitutionofthe pages 4-5, wild2019reconstitutionofthe pages 7-8)
SRP biogenesis/localization	SRP9/14 participates in nuclear/nucleolar phases of SRP assembly; most SRP proteins assemble with 7SL in the nucleus/nucleolus before final cytoplasmic maturation.	Review of assembly data/in vitro assembly	Ordered assembly summarized as SRP19 → SRP68/72 → SRP9/14 on 7SL RNA before cytoplasmic completion with SRP54.	Kellogg et al., 2021, Int J Mol Sci. https://doi.org/10.3390/ijms22126284	(kellogg2021srpassingcotranslationaltargeting pages 11-13, kellogg2021srpassingcotranslationaltargeting pages 6-7)
SRP biogenesis/localization	GFP-SRP9 is found mostly in the nucleus with faint cytoplasmic signal; SRP9/14 heterodimer accumulates in nucleoplasm, and nucleolar integrity is required for proper SRP protein localization.	Microscopy, GFP-trap IP, SILAC proteomics	Study identified 95 newly found nucleolar/ribosome-biogenesis-related SRP interactors, bringing total SRP-associated nucleolar/ribosome biogenesis factors to 173.	Issa et al., 2024, Life Science Alliance. https://doi.org/10.26508/lsa.202402614	(issa2024thenucleolarphase pages 3-5, issa2024thenucleolarphase pages 9-10, issa2024thenucleolarphase pages 1-2)
SRP biogenesis/localization	In SR receptor knockout cells, SRP9 protein remains present and SRP complex composition is retained, indicating SR loss does not collapse SRP abundance.	TMT-SILAC proteomics	In membrane proteome analysis, only ~25% of 287 polytopic and ~20% of 350 single-pass membrane proteins were downregulated; SRP9, SRP14, SRP19, SRP54, SRP68, SRP72 were still detected in both channels.	Child et al., 2023, RNA. https://doi.org/10.1261/rna.079643.123	(child2023examiningsrppathway pages 6-8)
Alu/retrotransposition	SRP9/14-bound Alu RNP mimics the SRP Alu domain and occupies the ribosomal elongation factor-binding site, linking ribosome stalling to Alu retrotransposition.	Structure/mutagenesis/retrotransposition assays	PDB 5AOX; mutations weakening SRP9/14 interaction by >3.5 kcal/mol abolish retrotransposition; exemplar constructs showed ~111%, 11%, and 83% relative activities depending on retained folding features.	Ahl et al., 2015, Molecular Cell. https://doi.org/10.1016/j.molcel.2015.10.003	(ahl2015retrotranspositionandcrystal pages 3-4, ahl2015retrotranspositionandcrystal pages 9-11, ahl2015retrotranspositionandcrystal pages 11-12, ahl2015retrotranspositionandcrystal media 866dee84)
Alu/retrotransposition	SRP9/14 binds 7SL and related Alu RNAs with high affinity and exists in substantial molar excess over assembled SRP, enabling extensive extra-canonical regulation of Alu-family RNAs.	Review synthesis of primary biochemical studies	Human SRP9/14 binds 7SL with sub-nanomolar affinity; primate SRP9/14 is present at ~20-fold molar excess over intact SRP; Alu elements comprise ~10% of the human genome.	Gussakovsky et al., 2024, RNA Biology. https://doi.org/10.1080/15476286.2024.2430817	(gussakovsky2024theroleof pages 1-2, gussakovsky2024theroleof pages 2-4)
Splicing regulation	SRP9/14 binds compact/closed Alu RNA conformations and modulates exonization of Alu-derived exons, acting functionally like an RNA chaperone in pre-mRNA splicing decisions.	Structure-guided mutagenesis, pull-down/immunoblot, footprinting, RNAi splicing assays	Splicing analysis covered 38 reporters; ~15 endogenous transcripts screened; six additional endogenous SRP9/14-regulated Alu exons identified; 16.5 µg recombinant SRP9/14 used in footprinting; SRP9/14 is ~20-fold in excess over SRP.	Borovská et al., 2023, Nucleic Acids Research. https://doi.org/10.1093/nar/gkad500	(borovska2023alurnafold pages 9-11, borovska2023alurnafold pages 11-14, borovska2023alurnafold pages 14-15, borovska2023alurnafold pages 5-6)
SRP biogenesis/localization	Nuclear SRP9/SRP14 positively regulates steady-state 7SL and BC200 levels by promoting transcription rather than RNA stability.	ChIP-qPCR, siRNA knockdown, BRIC/actinomycin D decay assays, fractionation	7SL reduced ~40% by 72 h knockdown; BC200 reduced >80% by 48 h and ~95% by 72 h; 7SL half-life 1.7 h (95% CI 1.4–2.1), BC200 1.5 h (95% CI 1.3–1.6); Pol III occupancy at 7SL fell ~15% at 48 h (P=1.3×10^-2) and ~15% at 72 h (P=6.5×10^-5); BC200 occupancy fell 15% (P=6.8×10^-3), 32% (P=2.0×10^-3), 48% (P=1.9×10^-4).	Gussakovsky et al., 2023, RNA. https://doi.org/10.1261/rna.079649.123	(gussakovsky2023nuclearsrp9srp14heterodimer pages 3-5, gussakovsky2023nuclearsrp9srp14heterodimer pages 2-3, gussakovsky2023nuclearsrp9srp14heterodimer pages 5-7, gussakovsky2023nuclearsrp9srp14heterodimer pages 7-8, gussakovsky2023nuclearsrp9srp14heterodimer pages 10-12)
Disease/biomarker	In pancreatic ductal adenocarcinoma, higher nuclear SRP9 localization is associated with better recurrence-free survival and with distinct translation/cancer-pathway RNA associations.	IHC, immunocytochemistry, splice-variant transfection, RIP-seq	Surgical cohort n=38; >50% nuclear-staining group n=24 vs ≤50% group n=14; better RFS P=0.037; OS not significant P=0.604; Ki-67 correlation R²=0.007, P=0.622; lymphatic invasion distribution differed (ly0:ly1 = 5:9 vs 17:7, P=0.047); amino-acid deficiency lowered nuclear translocation with P<0.0001 in cell assays.	Sato et al., 2024, International Journal of Oncology. https://doi.org/10.3892/ijo.2024.5662	(sato2024significanceofsignal pages 11-12, sato2024significanceofsignal pages 12-13, sato2024significanceofsignal pages 1-2, sato2024significanceofsignal pages 13-15, sato2024significanceofsignal pages 5-8)
Disease/biomarker	Public genetics/functional-association resources connect SRP9 to several disease areas, but current evidence is indirect and driven largely by functional-genomics datasets rather than established clinical causality.	Database association/functional genomics aggregation	Open Targets scores: neurodegenerative disease 0.542; abnormality of skeletal system 0.450; osteoarthritis 0.413; osteoarthritis, knee 0.331; lysosomal storage disease 0.109; evidence count 5 per listed association.	Open Targets Platform query for SRP9, accessed via tool context. https://platform.opentargets.org	(OpenTargets Search: -SRP9)

Table: This table summarizes the strongest mechanistic, localization, regulatory, and disease-linked evidence for human SRP9 (UniProt P49458). It emphasizes the distinction between canonical SRP/Alu-domain functions and emerging nuclear, splicing, and biomarker-related roles supported by recent literature and database evidence.

References

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(wild2019reconstitutionofthe pages 5-5): Klemens Wild, Keven D Juaire, Komal Soni, Vivekanandan Shanmuganathan, Astrid Hendricks, Bernd Segnitz, Roland Beckmann, and Irmgard Sinning. Reconstitution of the human srp system and quantitative and systematic analysis of its ribosome interactions. Nucleic Acids Research, 47:3184-3196, Jan 2019. URL: https://doi.org/10.1093/nar/gky1324, doi:10.1093/nar/gky1324. This article has 43 citations and is from a highest quality peer-reviewed journal.
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(wild2019reconstitutionofthe pages 6-7): Klemens Wild, Keven D Juaire, Komal Soni, Vivekanandan Shanmuganathan, Astrid Hendricks, Bernd Segnitz, Roland Beckmann, and Irmgard Sinning. Reconstitution of the human srp system and quantitative and systematic analysis of its ribosome interactions. Nucleic Acids Research, 47:3184-3196, Jan 2019. URL: https://doi.org/10.1093/nar/gky1324, doi:10.1093/nar/gky1324. This article has 43 citations and is from a highest quality peer-reviewed journal.
(OpenTargets Search: -SRP9): Open Targets Query (-SRP9, 5 results). Buniello, A. et al. (2025). Open Targets Platform: facilitating therapeutic hypotheses building in drug discovery. Nucleic Acids Research.
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(ahl2015retrotranspositionandcrystal media c0bafdb5): Valentina Ahl, Heiko Keller, Steffen Schmidt, and Oliver Weichenrieder. Retrotransposition and crystal structure of an alu rnp in the ribosome-stalling conformation. Molecular cell, 60 5:715-727, Dec 2015. URL: https://doi.org/10.1016/j.molcel.2015.10.003, doi:10.1016/j.molcel.2015.10.003. This article has 92 citations and is from a highest quality peer-reviewed journal.
(ahl2015retrotranspositionandcrystal pages 1-3): Valentina Ahl, Heiko Keller, Steffen Schmidt, and Oliver Weichenrieder. Retrotransposition and crystal structure of an alu rnp in the ribosome-stalling conformation. Molecular cell, 60 5:715-727, Dec 2015. URL: https://doi.org/10.1016/j.molcel.2015.10.003, doi:10.1016/j.molcel.2015.10.003. This article has 92 citations and is from a highest quality peer-reviewed journal.
(voorhees2015structuresofthe pages 6-7): Rebecca M Voorhees and Ramanujan S Hegde. Structures of the scanning and engaged states of the mammalian srp-ribosome complex. eLife, Jul 2015. URL: https://doi.org/10.7554/elife.07975, doi:10.7554/elife.07975. This article has 172 citations and is from a domain leading peer-reviewed journal.
(wild2019reconstitutionofthe pages 4-5): Klemens Wild, Keven D Juaire, Komal Soni, Vivekanandan Shanmuganathan, Astrid Hendricks, Bernd Segnitz, Roland Beckmann, and Irmgard Sinning. Reconstitution of the human srp system and quantitative and systematic analysis of its ribosome interactions. Nucleic Acids Research, 47:3184-3196, Jan 2019. URL: https://doi.org/10.1093/nar/gky1324, doi:10.1093/nar/gky1324. This article has 43 citations and is from a highest quality peer-reviewed journal.
(wild2019reconstitutionofthe pages 7-8): Klemens Wild, Keven D Juaire, Komal Soni, Vivekanandan Shanmuganathan, Astrid Hendricks, Bernd Segnitz, Roland Beckmann, and Irmgard Sinning. Reconstitution of the human srp system and quantitative and systematic analysis of its ribosome interactions. Nucleic Acids Research, 47:3184-3196, Jan 2019. URL: https://doi.org/10.1093/nar/gky1324, doi:10.1093/nar/gky1324. This article has 43 citations and is from a highest quality peer-reviewed journal.
(kellogg2021srpassingcotranslationaltargeting pages 6-7): Morgana K. Kellogg, Sarah C. Miller, Elena B. Tikhonova, and Andrey L. Karamyshev. Srpassing co-translational targeting: the role of the signal recognition particle in protein targeting and mrna protection. International Journal of Molecular Sciences, 22:6284, Jun 2021. URL: https://doi.org/10.3390/ijms22126284, doi:10.3390/ijms22126284. This article has 70 citations.
(issa2024thenucleolarphase pages 1-2): Amani Issa, Florence Schlotter, Justine Flayac, Jing Chen, Ludivine Wacheul, Manon Philippe, Lucas Sardini, Lalia Mostefa, Franck Vandermoere, Edouard Bertrand, Céline Verheggen, Denis LJ Lafontaine, and Séverine Massenet. The nucleolar phase of signal recognition particle assembly. Life Science Alliance, 7:e202402614, Jun 2024. URL: https://doi.org/10.26508/lsa.202402614, doi:10.26508/lsa.202402614. This article has 8 citations and is from a peer-reviewed journal.
(child2023examiningsrppathway pages 6-8): Jessica R. Child, Alex C. Hofler, Qiang Chen, Brenda H. Yang, JohnCarlo Kristofich, Tianli Zheng, Molly M. Hannigan, Andrew L. Elles, David W. Reid, and Christopher V. Nicchitta. Examining srp pathway function in mrna localization to the endoplasmic reticulum. RNA, 29:1703-1724, Aug 2023. URL: https://doi.org/10.1261/rna.079643.123, doi:10.1261/rna.079643.123. This article has 13 citations and is from a domain leading peer-reviewed journal.
(borovska2023alurnafold pages 11-14): Ivana Borovská, Igor Vořechovský, and Jana Královičová. Alu rna fold links splicing with signal recognition particle proteins. Nucleic Acids Research, 51:8199-8216, Jun 2023. URL: https://doi.org/10.1093/nar/gkad500, doi:10.1093/nar/gkad500. This article has 10 citations and is from a highest quality peer-reviewed journal.
(borovska2023alurnafold pages 14-15): Ivana Borovská, Igor Vořechovský, and Jana Královičová. Alu rna fold links splicing with signal recognition particle proteins. Nucleic Acids Research, 51:8199-8216, Jun 2023. URL: https://doi.org/10.1093/nar/gkad500, doi:10.1093/nar/gkad500. This article has 10 citations and is from a highest quality peer-reviewed journal.
(borovska2023alurnafold pages 5-6): Ivana Borovská, Igor Vořechovský, and Jana Královičová. Alu rna fold links splicing with signal recognition particle proteins. Nucleic Acids Research, 51:8199-8216, Jun 2023. URL: https://doi.org/10.1093/nar/gkad500, doi:10.1093/nar/gkad500. This article has 10 citations and is from a highest quality peer-reviewed journal.
(gussakovsky2023nuclearsrp9srp14heterodimer pages 7-8): Daniel Gussakovsky, Evan P. Booy, Mira J.F. Brown, and Sean A. McKenna. Nuclear srp9/srp14 heterodimer transcriptionally regulates 7sl and bc200 rna expression. RNA, 29:1185-1200, May 2023. URL: https://doi.org/10.1261/rna.079649.123, doi:10.1261/rna.079649.123. This article has 7 citations and is from a domain leading peer-reviewed journal.
(gussakovsky2023nuclearsrp9srp14heterodimer pages 10-12): Daniel Gussakovsky, Evan P. Booy, Mira J.F. Brown, and Sean A. McKenna. Nuclear srp9/srp14 heterodimer transcriptionally regulates 7sl and bc200 rna expression. RNA, 29:1185-1200, May 2023. URL: https://doi.org/10.1261/rna.079649.123, doi:10.1261/rna.079649.123. This article has 7 citations and is from a domain leading peer-reviewed journal.
(sato2024significanceofsignal pages 1-2): Hiromichi Sato, Sikun Meng, Kazuki Sasaki, Shogo Kobayashi, Kansuke Kido, Yoshiko Tsuji, Yasuko Arao, Yoshiko Saito, Yoshifumi Iwagami, Daisaku Yamada, Yoshito Tomimaru, Takehiro Noda, Hidenori Takahashi, Daisuke Motooka, Shizuka Uchida, Ken Ofusa, Taroh Satoh, Yuichiro Doki, Hidetoshi Eguchi, Tomoaki Hara, and Hideshi Ishii. Significance of signal recognition particle 9 nuclear translocation: implications for pancreatic cancer prognosis and functionality. International Journal of Oncology, Jun 2024. URL: https://doi.org/10.3892/ijo.2024.5662, doi:10.3892/ijo.2024.5662. This article has 0 citations and is from a peer-reviewed journal.
(sato2024significanceofsignal pages 13-15): Hiromichi Sato, Sikun Meng, Kazuki Sasaki, Shogo Kobayashi, Kansuke Kido, Yoshiko Tsuji, Yasuko Arao, Yoshiko Saito, Yoshifumi Iwagami, Daisaku Yamada, Yoshito Tomimaru, Takehiro Noda, Hidenori Takahashi, Daisuke Motooka, Shizuka Uchida, Ken Ofusa, Taroh Satoh, Yuichiro Doki, Hidetoshi Eguchi, Tomoaki Hara, and Hideshi Ishii. Significance of signal recognition particle 9 nuclear translocation: implications for pancreatic cancer prognosis and functionality. International Journal of Oncology, Jun 2024. URL: https://doi.org/10.3892/ijo.2024.5662, doi:10.3892/ijo.2024.5662. This article has 0 citations and is from a peer-reviewed journal.

Artifacts

Edison artifact artifact-00

Citations

child2023examiningsrppathway pages 6-8
faoro2021noncanonicalfunctionsand pages 3-4
kellogg2021srpassingcotranslationaltargeting pages 11-13
voorhees2015structuresofthe pages 7-9
voorhees2015structuresofthe pages 12-14
voorhees2015structuresofthe pages 14-15
wild2019reconstitutionofthe pages 1-2
ahl2015retrotranspositionandcrystal pages 5-6
ahl2015retrotranspositionandcrystal pages 6-7
borovska2023alurnafold pages 1-2
borovska2023alurnafold pages 9-11
issa2024thenucleolarphase pages 9-10
issa2024thenucleolarphase pages 3-5
gussakovsky2024theroleof pages 1-2
gussakovsky2024theroleof pages 2-4
sato2024significanceofsignal pages 11-12
sato2024significanceofsignal pages 12-13
sato2024significanceofsignal pages 5-8
ahl2015retrotranspositionandcrystal pages 3-4
ahl2015retrotranspositionandcrystal pages 11-12
voorhees2015structuresofthe pages 9-10
wild2019reconstitutionofthe pages 10-11
wild2019reconstitutionofthe pages 5-5
ahl2015retrotranspositionandcrystal pages 9-11
wild2019reconstitutionofthe pages 6-7
ahl2015retrotranspositionandcrystal pages 1-3
voorhees2015structuresofthe pages 6-7
wild2019reconstitutionofthe pages 4-5
wild2019reconstitutionofthe pages 7-8
kellogg2021srpassingcotranslationaltargeting pages 6-7
issa2024thenucleolarphase pages 1-2
borovska2023alurnafold pages 11-14
borovska2023alurnafold pages 14-15
borovska2023alurnafold pages 5-6
sato2024significanceofsignal pages 1-2
sato2024significanceofsignal pages 13-15
https://doi.org/10.1261/rna.079649.123
https://doi.org/10.1093/nar/gkad500
https://doi.org/10.26508/lsa.202402614
https://doi.org/10.1080/15476286.2024.2430817
https://doi.org/10.3892/ijo.2024.5662
https://doi.org/10.1016/j.molcel.2015.10.003
https://doi.org/10.7554/eLife.07975
https://doi.org/10.1093/nar/gky1324
https://doi.org/10.3389/fmolb.2021.679584;
https://doi.org/10.3390/ijms22126284
https://doi.org/10.1261/rna.079643.123
https://platform.opentargets.org
https://doi.org/10.3389/fmolb.2021.679584,
https://doi.org/10.3390/ijms22126284,
https://doi.org/10.7554/elife.07975,
https://doi.org/10.1093/nar/gky1324,
https://doi.org/10.1016/j.molcel.2015.10.003,
https://doi.org/10.1261/rna.079649.123,
https://doi.org/10.1093/nar/gkad500,
https://doi.org/10.26508/lsa.202402614,
https://doi.org/10.1080/15476286.2024.2430817,
https://doi.org/10.3892/ijo.2024.5662,
https://doi.org/10.1261/rna.079643.123,

📚 Additional Documentation

Notes

(SRP9-notes.md)

SRP9 (P49458) review notes

Identity and overview

SRP9 is the 9 kDa subunit of the signal recognition particle (SRP). It is an 86-aa
protein (initiator Met removed; chain 2-86) belonging to the SRP9 family.

[file:human/SRP9/SRP9-uniprot.txt "Signal recognition particle 9 kDa protein"]

Core function: Alu domain / elongation arrest

SRP9 together with SRP14 and the Alu portion of the SRP RNA constitutes the
elongation-arrest domain of SRP. SRP9 binds RNA as a heterodimer with SRP14.

[file:human/SRP9/SRP9-uniprot.txt "SRP9 together with SRP14 and the Alu portion of the\nCC SRP RNA, constitutes the elongation arrest domain of SRP"]
[file:human/SRP9/SRP9-uniprot.txt "Heterodimer with SRP14; binds RNA as heterodimer"]
[file:human/SRP9/SRP9-uniprot.txt "The complex of SRP9 and SRP14 is required for SRP\nCC RNA binding"]

Review (PMID:34208095, full text available) describes the elongation arrest mechanism:
PMID:34208095
PMID:34208095
PMID:34208095
PMID:34208095

This supports:
- MF: SRP RNA / 7S RNA binding (GO:0008312) within SRP, as the SRP9/14 heterodimer
- BP: negative regulation of translational elongation (GO:0045900) — elongation arrest
- BP: SRP-dependent cotranslational protein targeting to membrane (GO:0006614)
- CC: signal recognition particle (GO:0005786 / GO:0048500)

Complex membership

SRP is a ribonucleoprotein of one 7SL RNA (~300 nt) and six proteins: SRP72, SRP68,
SRP54, SRP19, SRP14, SRP9. SRP9 forms the Alu-domain heterodimer with SRP14.
[file:human/SRP9/SRP9-uniprot.txt "Component of a signal recognition particle complex that\nCC consists of a 7SL RNA molecule of 300 nucleotides and six protein\nCC subunits: SRP72, SRP68, SRP54, SRP19, SRP14 and SRP9"]

ComplexPortal: CPX-2652 Signal recognition particle.
[file:human/SRP9/SRP9-uniprot.txt "ComplexPortal; CPX-2652; Signal recognition particle."]

Structural evidence: X-ray of SRP9 (2-86) in complex with SRP14 (PMID:11089964,
"Structure and assembly of the Alu domain of the mammalian signal recognition particle";
abstract NOT cached). Cryo-EM of SRP in complex with ribosome-nascent chain and SRP
receptor (PMID:34020957; abstract NOT cached). Both establish the Alu/elongation-arrest
geometry and SRP9 as an Alu-domain RNA-binding subunit — SRP9 itself is NOT a GTPase
(the GTPases in the pathway are SRP54, SRα, SRβ).
PMID:34208095

Original characterization (PMID:7730321, abstract only)

Hsu, Chang & Maraia 1995 characterized human SRP9; SRP9/14 = the Alu RNA-binding
protein (RBP); binds the Alu region of 7SL plus scAlu/scB1 RNAs with high affinity.
PMID:7730321
PMID:7730321
This GOA reference (PMID:7730321) underlies the TAS annotations RNA binding (GO:0003723)
and signal recognition particle binding (GO:0005047). It also was used (PINC) for a
GO:0005785 "signal recognition particle receptor complex" CC annotation — but the paper
is about SRP9 in SRP (the Alu RBP), not the SR (SRα/SRβ) receptor complex. SRP9 is a
component of SRP, not of the SRP receptor complex. GO:0005785 is likely a curation
mislabel (SRP vs SRP receptor confusion) and is an over/mis-annotation.

Subcellular location

UniProt: Cytoplasm. SRP9/14 colocalizes in the nucleolus during SRP biogenesis (review),
but the mature functional location is cytoplasm/cytosol.
[file:human/SRP9/SRP9-uniprot.txt "SUBCELLULAR LOCATION: Cytoplasm."]

protein binding (GO:0005515, IPI) annotations

Many IPI "protein binding" annotations exist. Several name SRP14 (P37108) as the partner
(PMID:28514442, 30021884, 32296183, 33961781, 35271311, 40205054) — this is the genuine,
biologically central SRP9-SRP14 Alu heterodimer interaction. UniProt INTERACTION block:
[file:human/SRP9/SRP9-uniprot.txt "P49458; P37108: SRP14; NbExp=12; IntAct=EBI-350743, EBI-353399;"]
Others name unrelated high-throughput partners: ACTN2/P35609 (PMID:25910212);
CDHR3/Q6ZTQ4, DPP9/Q86TI2-2, RYBP/Q8N488 (PMID:32814053). PMID:24965446 reports SRP9
co-purifying with the pestivirus Npro RNP complex (P19712-PRO_0000038050), an
incidental ribosomal/RNP capture. Bare "protein binding" is uninformative per curation
guidelines; keep as non-core (do not REMOVE experimental IPI annotations).

Conclusions for review actions

Core MF: 7S/SRP RNA binding (GO:0008312) as the SRP9/14 Alu heterodimer; RNA binding
(GO:0003723) is the correct but more general parent.
Core BP: SRP-dependent cotranslational protein targeting to membrane (GO:0006614);
negative regulation of translational elongation (GO:0045900, elongation arrest).
Core CC: signal recognition particle (GO:0005786 / GO:0048500).
GO:0005047 signal recognition particle binding (SRP9 binding to SRP) — acceptable but
non-core (SRP9 IS part of SRP rather than an external SRP-binding factor; redundant with
part_of SRP).
GO:0005785 SRP receptor complex (part_of) — MODIFY/over-annotation: SRP9 is part of SRP,
not the SRP receptor (SRα/SRβ) complex. Mark as over-annotated.
GO:0006617 signal sequence recognition (NAS, ComplexPortal): signal-sequence recognition
is SRP54's role, not SRP9's; SRP9 contributes elongation arrest. Keep as non-core
(it is a complex-level NAS annotation; SRP9 is part of the complex that performs this).

Falcon deep-research findings (incorporated 2026-06)

Structural basis of the SRP9/14 Alu-domain RNA clamp: 2.0 A crystal structure of the human Alu RNP (SRP9/14 + Alu RNA) in the ribosome-stalling conformation; the heterodimer clamps the RNA and docks at the ribosomal elongation-factor binding site PMID:26585389. Added (HIGH) and used to strengthen the core 7S-RNA-binding and elongation-arrest core_functions.
SRP9 contributes ~700 A^2 of the ~1,820 A^2 SRP9/14-RNA interface; mutations weakening the interface beyond DDG > 3.5 kcal/mol abolish Alu retrotransposition PMID:26585389. Links SRP9/14 binding energy to Alu retroelement activity.
Noncanonical nuclear role: SRP9/14 localizes substantially in the nucleus and transcriptionally regulates the Pol III Alu-like transcripts 7SL (RN7SL1) and BC200 (BCYRN1) by modulating Pol III occupancy rather than RNA stability PMID:37156570. Added (MEDIUM); not core SRP function.
Noncanonical splicing role: SRP9/14 binds closed/compact Alu RNA folds and regulates inclusion of Alu-derived exons (RNA structure predicts inclusion better than sequence motifs) PMID:37309897. Added (MEDIUM).
Nucleolar assembly phase: GFP-SRP9 is mostly nuclear; SRP proteins associate with many nucleolar/ribosome-biogenesis factors and nucleolar integrity is required for proper SRP localization PMID:38858088. Added (MEDIUM); supports a nuclear/nucleolar biogenesis compartment for SRP9.
Abundance/affinity context: primate SRP9/14 is present at ~20-fold molar excess over assembled SRP and binds 7SL with sub-nanomolar affinity, enabling extensive extra-canonical Alu-RNA regulation PMID:39563162. Added (MEDIUM, review).
Reconstitution work indicates SRP54 and SRP68/72 dominate measurable SRP-ribosome affinity while the Alu (SRP9/14) domain contributes little to affinity, consistent with SRP9/14's role being steric/regulatory at the factor-binding site rather than high-affinity docking (Wild et al. 2019, DOI 10.1093/nar/gky1324). Consistent with existing review framing; notes-only (not added).
Biomarker/association: higher SRP9 nuclear staining associates with improved recurrence-free survival in resected pancreatic cancer, modulated by nutrient/amino-acid status PMID:38847231. Added (LOW); association-level, not core function.

Pn Notes

(SRP9-pn-notes.md)

SRP9 PN Consistency Notes

Generated: 2026-06-18
Project: PROTEOSTASIS
Scope: PN consistency rereview against local AIGR review and available deep-research artifacts
UniProt: P49458
AIGR review status: COMPLETE
Review batch: proteostasis-batch-2026-06-11
Batch change status: added

Source Files Checked

AIGR review YAML: present - genes/human/SRP9/SRP9-ai-review.yaml
AIGR review HTML: missing - genes/human/SRP9/SRP9-ai-review.html
Gene notes: present - genes/human/SRP9/SRP9-notes.md
GOA TSV: present - genes/human/SRP9/SRP9-goa.tsv
UniProt record: present - genes/human/SRP9/SRP9-uniprot.txt
PN dossier: projects/PROTEOSTASIS/reports/phase1_dossiers/SRP9.md
PN consistency section: projects/PROTEOSTASIS/reports/phase1_dossiers/_sections/SRP9.md
PN projection report: projects/PROTEOSTASIS/reports/pn_projection/pn_projected_gene_go_summary.tsv
PN mapping audit: projects/PROTEOSTASIS/reports/pn_mapping_audit/current_mapping_scrutiny.tsv

Deep Research Files

genes/human/SRP9/SRP9-deep-research-falcon.md

AIGR Review Snapshot

Description: SRP9 is the 9 kDa subunit of the signal recognition particle (SRP), the cytosolic ribonucleoprotein that mediates co-translational targeting of secretory and membrane proteins to the endoplasmic reticulum (ER). SRP comprises a single 7SL RNA (~300 nucleotides) and six proteins (SRP9, SRP14, SRP19, SRP54, SRP68, SRP72). SRP9 binds the SRP RNA as an obligate heterodimer with SRP14, and together with the Alu portion of the SRP RNA forms the Alu domain at one end of the particle. This Alu domain is the elongation-arrest module of SRP. When SRP binds a ribosome translating a signal sequence, the SRP9/SRP14 heterodimer reaches into the ribosomal elongation-factor binding site and transiently pauses (arrests) translation elongation, giving SRP time to deliver the ribosome-nascent chain complex to the ER membrane SRP receptor. SRP9 is an RNA-binding protein rather than a GTPase (the GTPases of the pathway are SRP54 and the SRP-receptor subunits). It functions in the cytoplasm/cytosol; SRP9/SRP14 transit the nucleolus during SRP assembly.
Existing/core annotation action counts: ACCEPT: 12; KEEP_AS_NON_CORE: 11; MARK_AS_OVER_ANNOTATED: 1

PN Consistency Summary

Consistency: Strong and mutually consistent. Deep research, review YAML, and PN annotation all describe SRP9 as the 9 kDa SRP subunit that, with SRP14, forms the Alu/elongation-arrest domain bound to 7SL RNA. The PN "SRP component" label and GO:0006614 mapping match the review's core BP (GO:0006614 IBA/IEA, ACCEPT). No contradictions.
PN story / NEW pressure: PN asserts only the canonical SRP cotranslational-targeting role, already captured (GO:0006614 ACCEPT; plus the SRP9-specific GO:0045900 negative regulation of translational elongation and GO:0008312 7S RNA binding). Noncanonical Alu-RNA/nuclear roles (PMID:37156570, 37309897, 26585389) are in the review references but outside the PN story and not core. Conclusion: already captured (no NEW pressure).
Evidence alignment: PN dossier lists no reference titles; alignment via projected-term provenance. Review's core support (PMID:34208095 SRP review, elongation arrest; PMID:26585389 Alu-RNP ribosome-stalling structure; file UniProt) all encode the SRP cotranslational-targeting biology the PN maps to. No divergence.
Verdict: Fully consistent; PN already captured, review more granular (adds elongation-arrest GO:0045900 and 7S RNA binding). No edits warranted.

Full Consistency Review

UniProt: P49458 · batch: proteostasis-batch-2026-06-11 · review status: COMPLETE
PN placement: ER proteostasis|Protein transport|Signal recognition particle component ; PN-node mapping: group=mapped scope=ok_for_propagation_to_go→GO:0006614 (SRP-dependent cotranslational protein targeting to membrane); class Protein transport=mapped→GO:0015031; branch=no_mapping.
Consistency: Strong and mutually consistent. Deep research, review YAML, and PN annotation all describe SRP9 as the 9 kDa SRP subunit that, with SRP14, forms the Alu/elongation-arrest domain bound to 7SL RNA. The PN "SRP component" label and GO:0006614 mapping match the review's core BP (GO:0006614 IBA/IEA, ACCEPT). No contradictions.
PN story / NEW pressure: PN asserts only the canonical SRP cotranslational-targeting role, already captured (GO:0006614 ACCEPT; plus the SRP9-specific GO:0045900 negative regulation of translational elongation and GO:0008312 7S RNA binding). Noncanonical Alu-RNA/nuclear roles (PMID:37156570, 37309897, 26585389) are in the review references but outside the PN story and not core. Conclusion: already captured (no NEW pressure).
Mapping strategy: No change needed. GO:0006614 (goa_status already_in_goa_exact) is present and ACCEPTed — exact projection, not broader than the review. The class-level GO:0015031 is a deliberately broad class target, not asserted of SRP9 specifically. Note the review flags GO:0005785 (SRP receptor complex, TAS PMID:7730321) as over-annotated (SRP vs SRP-receptor confusion) — internal review QC unrelated to the PN node.
Evidence alignment: PN dossier lists no reference titles; alignment via projected-term provenance. Review's core support (PMID:34208095 SRP review, elongation arrest; PMID:26585389 Alu-RNP ribosome-stalling structure; file UniProt) all encode the SRP cotranslational-targeting biology the PN maps to. No divergence.
Verdict: Fully consistent; PN already captured, review more granular (adds elongation-arrest GO:0045900 and 7S RNA binding). No edits warranted.

PN Dossier Context

review_batch: proteostasis-batch-2026-06-11
review_yaml: genes/human/SRP9/SRP9-ai-review.yaml
PN workbook rows: 1

PN row 1: ER proteostasis | Protein transport | Signal recognition particle component

UniProt: P49458
In branches: ER
PN-node mapping records (path + ancestors):
- [group] ER proteostasis|Protein transport|Signal recognition particle component
  status=mapped scope=ok_for_propagation_to_go GO=[GO:0006614 SRP-dependent cotranslational protein targeting to membrane]
  rationale: This PN group captures core signal-recognition-particle machinery used to direct translating ribosome-nascent chain complexes to the ER membrane. The group is machinery-centric rather than process-equivalent, so it propagates to the GO targeting process.
- [class] ER proteostasis|Protein transport
  status=mapped scope=ok_for_propagation_to_go GO=[GO:0015031 protein transport]
  rationale: The PN ER Protein transport class groups ER-targeting and ER-insertion pathways. GO protein transport is the appropriate propagation target, while the source class remains ER-specific and broader than any single GO transport subtype.
- [branch] ER proteostasis
  status=no_mapping scope= GO=[]
  rationale: Reviewed as a top-level PN branch. This is a systems/taxonomy umbrella, not a direct GO assertion; narrower child curations carry any propagating GO mappings.

Projected GO annotations (2)

GO:0015031 protein transport | scope=ok_for_propagation_to_go | goa_status=new_to_goa | from=ER proteostasis|Protein transport
GO:0006614 SRP-dependent cotranslational protein targeting to membrane | scope=ok_for_propagation_to_go | goa_status=already_in_goa_exact | from=ER proteostasis|Protein transport|Signal recognition particle component

Note

This file is generated from the current PROTEOSTASIS phase-1 dossier and local gene-review artifacts. Edit the source review, PN mapping, or dossier rather than this generated note when correcting the underlying curation.

📄 View Raw YAML

id: P49458
gene_symbol: SRP9
product_type: PROTEIN
status: COMPLETE
taxon:
  id: NCBITaxon:9606
  label: Homo sapiens
description: 'SRP9 is the 9 kDa subunit of the signal recognition particle (SRP), the cytosolic ribonucleoprotein that mediates co-translational targeting of secretory and membrane proteins to the endoplasmic reticulum (ER). SRP comprises a single 7SL RNA (~300 nucleotides) and six proteins (SRP9, SRP14, SRP19, SRP54, SRP68, SRP72). SRP9 binds the SRP RNA as an obligate heterodimer with SRP14, and together with the Alu portion of the SRP RNA forms the Alu domain at one end of the particle. This Alu domain is the elongation-arrest module of SRP. When SRP binds a ribosome translating a signal sequence, the SRP9/SRP14 heterodimer reaches into the ribosomal elongation-factor binding site and transiently pauses (arrests) translation elongation, giving SRP time to deliver the ribosome-nascent chain complex to the ER membrane SRP receptor. SRP9 is an RNA-binding protein rather than a GTPase (the GTPases of the pathway are SRP54 and the SRP-receptor subunits). It functions in the cytoplasm/cytosol; SRP9/SRP14 transit the nucleolus during SRP assembly.'
alternative_products:
- name: '1'
  id: P49458-1
- name: '2'
  id: P49458-2
  sequence_note: VSP_041270
existing_annotations:
- term:
    id: GO:0006614
    label: SRP-dependent cotranslational protein targeting to membrane
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  qualifier: involved_in
  review:
    summary: Phylogenetic annotation of SRP9's defining biological process. As part of SRP, SRP9 (via the Alu/elongation-arrest domain) contributes to SRP-dependent co-translational targeting of proteins to the ER membrane. Conserved across the SRP9 family.
    action: ACCEPT
    reason: Core biological process; SRP9 is an SRP subunit essential to co-translational ER targeting.
    supported_by:
    - reference_id: file:human/SRP9/SRP9-uniprot.txt
      supporting_text: mediates the cotranslational targeting
- term:
    id: GO:0005786
    label: signal recognition particle, endoplasmic reticulum targeting
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  qualifier: part_of
  review:
    summary: Phylogenetic annotation of SRP9 as a constitutive subunit of the signal recognition particle. Conserved and directly established.
    action: ACCEPT
    reason: Core cellular component; SRP9 is one of the six SRP protein subunits.
    supported_by:
    - reference_id: file:human/SRP9/SRP9-uniprot.txt
      supporting_text: 'consists of a 7SL RNA molecule of 300 nucleotides and six protein'
- term:
    id: GO:0005737
    label: cytoplasm
  evidence_type: IEA
  original_reference_id: GO_REF:0000044
  qualifier: located_in
  review:
    summary: Electronic transfer of the cytoplasmic localization from the UniProt subcellular location. SRP functions in the cytoplasm targeting nascent chains to the ER.
    action: ACCEPT
    reason: Correct compartment; SRP acts in the cytoplasm.
    supported_by:
    - reference_id: file:human/SRP9/SRP9-uniprot.txt
      supporting_text: 'SUBCELLULAR LOCATION: Cytoplasm.'
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: IEA
  original_reference_id: GO_REF:0000117
  qualifier: located_in
  review:
    summary: ARBA machine-learning electronic annotation of cytosolic localization, consistent with the cytoplasmic site of SRP function.
    action: ACCEPT
    reason: Correct compartment; consistent with UniProt cytoplasm and Reactome cytosol.
    supported_by:
    - reference_id: file:human/SRP9/SRP9-uniprot.txt
      supporting_text: 'SUBCELLULAR LOCATION: Cytoplasm.'
- term:
    id: GO:0006614
    label: SRP-dependent cotranslational protein targeting to membrane
  evidence_type: IEA
  original_reference_id: GO_REF:0000002
  qualifier: involved_in
  review:
    summary: InterPro-based electronic assignment of the core SRP-dependent co-translational targeting process.
    action: ACCEPT
    reason: Correct core process; redundant with IBA/NAS evidence.
    supported_by:
    - reference_id: file:human/SRP9/SRP9-uniprot.txt
      supporting_text: mediates the cotranslational targeting
- term:
    id: GO:0008312
    label: 7S RNA binding
  evidence_type: IEA
  original_reference_id: GO_REF:0000002
  qualifier: enables
  review:
    summary: InterPro-based annotation of SRP RNA (7S/7SL) binding. SRP9 binds the SRP 7SL RNA as part of the SRP9/SRP14 Alu-domain heterodimer; this RNA-binding is its core molecular function.
    action: ACCEPT
    reason: Core molecular function; SRP9 (with SRP14) binds the Alu portion of the SRP RNA.
    supported_by:
    - reference_id: file:human/SRP9/SRP9-uniprot.txt
      supporting_text: The complex of SRP9 and SRP14 is required for SRP
- term:
    id: GO:0045900
    label: negative regulation of translational elongation
  evidence_type: IEA
  original_reference_id: GO_REF:0000002
  qualifier: involved_in
  review:
    summary: InterPro-based annotation of the elongation-arrest function. The SRP9/SRP14 Alu domain transiently arrests translation elongation by reaching into the ribosomal elongation-factor binding site. This is the defining SRP9-specific contribution to SRP function.
    action: ACCEPT
    reason: Core biological process; SRP9 is part of the Alu/elongation-arrest domain that negatively regulates elongation.
    supported_by:
    - reference_id: PMID:34208095
      supporting_text: SRP9 and SRP14 function in elongation arrest
- term:
    id: GO:0048500
    label: signal recognition particle
  evidence_type: IEA
  original_reference_id: GO_REF:0000002
  qualifier: part_of
  review:
    summary: InterPro-based annotation of SRP complex membership (general SRP term). SRP9 is a constitutive subunit.
    action: ACCEPT
    reason: Core cellular component; redundant with the more specific GO:0005786.
    supported_by:
    - reference_id: file:human/SRP9/SRP9-uniprot.txt
      supporting_text: 'Component of the signal recognition particle (SRP) complex'
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:25910212
  qualifier: enables
  review:
    summary: High-throughput interactome screen; the captured partner (ACTN2) is unrelated to SRP9's function. Bare protein binding is uninformative.
    action: KEEP_AS_NON_CORE
    reason: Incidental high-throughput interaction; bare protein binding is uninformative.
    supported_by:
    - reference_id: file:human/SRP9/SRP9-uniprot.txt
      supporting_text: 'P49458; P35609: ACTN2'
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:28514442
  qualifier: enables
  review:
    summary: Human interactome study capturing the functionally central SRP9-SRP14 (P37108) Alu-heterodimer interaction. Biologically meaningful but the bare protein binding term is uninformative.
    action: KEEP_AS_NON_CORE
    reason: Records the real SRP14 heterodimer interaction, but bare protein binding is uninformative; the informative MF is captured by GO:0008312 and complex membership by GO:0005786.
    supported_by:
    - reference_id: file:human/SRP9/SRP9-uniprot.txt
      supporting_text: 'P49458; P37108: SRP14'
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:30021884
  qualifier: enables
  review:
    summary: Crosslinking-MS interactome capturing the SRP9-SRP14 (P37108) interaction. Bare protein binding is uninformative.
    action: KEEP_AS_NON_CORE
    reason: Records the real SRP14 interaction; bare protein binding is uninformative.
    supported_by:
    - reference_id: file:human/SRP9/SRP9-uniprot.txt
      supporting_text: 'P49458; P37108: SRP14'
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:32296183
  qualifier: enables
  review:
    summary: HuRI binary interactome capturing the SRP9-SRP14 (P37108) interaction. Bare protein binding is uninformative.
    action: KEEP_AS_NON_CORE
    reason: Records the real SRP14 interaction; bare protein binding is uninformative.
    supported_by:
    - reference_id: file:human/SRP9/SRP9-uniprot.txt
      supporting_text: 'P49458; P37108: SRP14'
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:32814053
  qualifier: enables
  review:
    summary: Neurodegenerative-disease interactome mapping; captured partners (CDHR3, DPP9, RYBP) are unrelated to SRP9's function. Bare protein binding is uninformative.
    action: KEEP_AS_NON_CORE
    reason: Incidental high-throughput interactions; bare protein binding is uninformative.
    supported_by:
    - reference_id: file:human/SRP9/SRP9-uniprot.txt
      supporting_text: 'P49458; Q6ZTQ4: CDHR3'
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:33961781
  qualifier: enables
  review:
    summary: Proteome-scale interactome capturing the SRP9-SRP14 (P37108) interaction. Bare protein binding is uninformative.
    action: KEEP_AS_NON_CORE
    reason: Records the real SRP14 interaction; bare protein binding is uninformative.
    supported_by:
    - reference_id: file:human/SRP9/SRP9-uniprot.txt
      supporting_text: 'P49458; P37108: SRP14'
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:35271311
  qualifier: enables
  review:
    summary: OpenCell endogenous-tagging interactome capturing the SRP9-SRP14 (P37108) interaction. Bare protein binding is uninformative.
    action: KEEP_AS_NON_CORE
    reason: Records the real SRP14 interaction; bare protein binding is uninformative.
    supported_by:
    - reference_id: file:human/SRP9/SRP9-uniprot.txt
      supporting_text: 'P49458; P37108: SRP14'
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:40205054
  qualifier: enables
  review:
    summary: Multimodal cell map capturing the SRP9-SRP14 (P37108) interaction. Bare protein binding is uninformative.
    action: KEEP_AS_NON_CORE
    reason: Records the real SRP14 interaction; bare protein binding is uninformative.
    supported_by:
    - reference_id: file:human/SRP9/SRP9-uniprot.txt
      supporting_text: 'P49458; P37108: SRP14'
- term:
    id: GO:0005786
    label: signal recognition particle, endoplasmic reticulum targeting
  evidence_type: NAS
  original_reference_id: PMID:34208095
  qualifier: part_of
  review:
    summary: ComplexPortal NAS assertion of SRP complex membership, from the SRP review describing the SRP9/SRP14 Alu domain.
    action: ACCEPT
    reason: Core cellular component; SRP9 is an SRP subunit.
    supported_by:
    - reference_id: PMID:34208095
      supporting_text: 'Alu domain'
- term:
    id: GO:0006617
    label: SRP-dependent cotranslational protein targeting to membrane, signal sequence recognition
  evidence_type: NAS
  original_reference_id: PMID:34208095
  qualifier: involved_in
  review:
    summary: ComplexPortal NAS (complex-level) annotation of signal-sequence recognition. Signal-sequence recognition is performed by the SRP54 subunit of the SRP, not directly by SRP9, whose specific role is elongation arrest within the Alu domain. The term applies at the SRP complex level of which SRP9 is part.
    action: KEEP_AS_NON_CORE
    reason: Complex-level NAS annotation; signal-sequence recognition is the SRP54 function, while SRP9's direct contribution is elongation arrest.
    supported_by:
    - reference_id: PMID:34208095
      supporting_text: signal sequence
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:24965446
  qualifier: enables
  review:
    summary: SRP9 co-purifies with the pestivirus Npro ribonucleoprotein complex; an incidental ribosomal/RNP capture from a viral interactome study. Bare protein binding is uninformative.
    action: KEEP_AS_NON_CORE
    reason: Incidental viral RNP co-purification; bare protein binding is uninformative.
    supported_by:
    - reference_id: PMID:24965446
      supporting_text: components of the ribonucleoprotein complex
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-1799332
  qualifier: located_in
  review:
    summary: Reactome curation of cytosolic localization, consistent with SRP's cytoplasmic site of action.
    action: ACCEPT
    reason: Correct compartment; redundant with UniProt cytoplasm.
    supported_by:
    - reference_id: file:human/SRP9/SRP9-uniprot.txt
      supporting_text: 'SUBCELLULAR LOCATION: Cytoplasm.'
- term:
    id: GO:0005786
    label: signal recognition particle, endoplasmic reticulum targeting
  evidence_type: NAS
  original_reference_id: PMID:17154533
  qualifier: part_of
  review:
    summary: NAS assertion of SRP complex membership from a study on compartmentalized SRP assembly.
    action: ACCEPT
    reason: Core cellular component; SRP9 is an SRP subunit.
    supported_by:
    - reference_id: PMID:17154533
      supporting_text: Compartmentalization directs assembly of the signal recognition particle
- term:
    id: GO:0003723
    label: RNA binding
  evidence_type: TAS
  original_reference_id: PMID:7730321
  qualifier: enables
  review:
    summary: SRP9 (with SRP14) is the Alu RNA-binding protein that binds the Alu region of 7SL RNA. RNA binding is correct but is the general parent of the more specific 7S RNA binding.
    action: ACCEPT
    reason: Correct molecular function; the more specific GO:0008312 (7S RNA binding) better captures SRP9's role.
    supported_by:
    - reference_id: PMID:7730321
      supporting_text: regulates translational elongation of
- term:
    id: GO:0005047
    label: signal recognition particle binding
  evidence_type: TAS
  original_reference_id: PMID:7730321
  qualifier: enables
  review:
    summary: Annotation of SRP9 binding the signal recognition particle. SRP9 is itself a constitutive subunit of SRP rather than an external SRP-binding factor, so this is redundant with its part_of SRP membership.
    action: KEEP_AS_NON_CORE
    reason: SRP9 is part of SRP (captured by GO:0005786); describing it as SRP-binding is redundant and not the informative core MF.
    supported_by:
    - reference_id: file:human/SRP9/SRP9-uniprot.txt
      supporting_text: 'consists of a 7SL RNA molecule of 300 nucleotides and six protein'
- term:
    id: GO:0005785
    label: signal recognition particle receptor complex
  evidence_type: TAS
  original_reference_id: PMID:7730321
  qualifier: part_of
  review:
    summary: SRP9 is annotated as part of the signal recognition particle receptor (SR) complex. This is incorrect; PMID:7730321 characterizes SRP9 as a component of the SRP (the Alu RNA-binding protein), not of the SRP receptor (SRalpha/SRbeta) complex. This appears to be an SRP-versus-SRP-receptor curation confusion.
    action: MARK_AS_OVER_ANNOTATED
    reason: SRP9 is a subunit of SRP, not of the SRP receptor complex; the cited paper concerns SRP9 within SRP, so this CC is a mis-/over-annotation.
    supported_by:
    - reference_id: PMID:7730321
      supporting_text: regulates translational elongation of
references:
- id: GO_REF:0000002
  title: Gene Ontology annotation through association of InterPro records with GO terms
  findings: []
- id: GO_REF:0000033
  title: Annotation inferences using phylogenetic trees
  findings: []
- id: GO_REF:0000044
  title: Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location vocabulary mapping
  findings: []
- id: GO_REF:0000117
  title: Electronic Gene Ontology annotations created by ARBA machine learning models
  findings: []
- id: PMID:7730321
  title: Human signal recognition particle (SRP) Alu-associated protein also binds Alu interspersed repeat sequence RNAs. Characterization of human SRP9.
  findings:
  - statement: SRP9 with SRP14 (SRP9/14) is the Alu RNA-binding protein that binds the Alu region of 7SL RNA and regulates translational elongation of ribosomes engaged by SRP.
    reference_section_type: ABSTRACT
  reference_review:
    relevance: HIGH
    correctness: VERIFIED
    review_notes: Characterizes human SRP9 as the Alu RNA-binding protein within SRP; concerns SRP (not the SRP receptor).
- id: PMID:17154533
  title: Compartmentalization directs assembly of the signal recognition particle.
  findings:
  - statement: Describes compartmentalized (nucleolar/cytoplasmic) assembly of SRP, of which SRP9 is a subunit.
    reference_section_type: ABSTRACT
  reference_review:
    relevance: MEDIUM
    correctness: VERIFIED
    review_notes: Source of an SRP complex-membership NAS annotation.
- id: PMID:24965446
  title: Host factors that interact with the pestivirus N-terminal protease, Npro, are components of the ribonucleoprotein complex.
  findings: []
  reference_review:
    relevance: LOW
    correctness: VERIFIED
    review_notes: Viral RNP interactome; SRP9 co-purifies incidentally as a ribosomal/RNP component.
- id: PMID:25910212
  title: Widespread macromolecular interaction perturbations in human genetic disorders.
  findings: []
  reference_review:
    relevance: LOW
    correctness: VERIFIED
    review_notes: High-throughput interactome; incidental ACTN2 partner, bare protein binding.
- id: PMID:28514442
  title: Architecture of the human interactome defines protein communities and disease networks.
  findings: []
  reference_review:
    relevance: MEDIUM
    correctness: VERIFIED
    review_notes: Captures the functionally central SRP9-SRP14 interaction; bare protein binding term.
- id: PMID:30021884
  title: Histone Interaction Landscapes Visualized by Crosslinking Mass Spectrometry in Intact Cell Nuclei.
  findings: []
  reference_review:
    relevance: LOW
    correctness: VERIFIED
    review_notes: Crosslinking-MS; captures SRP14 interaction, bare protein binding.
- id: PMID:32296183
  title: A reference map of the human binary protein interactome.
  findings: []
  reference_review:
    relevance: MEDIUM
    correctness: VERIFIED
    review_notes: HuRI Y2H; captures SRP9-SRP14 interaction, bare protein binding.
- id: PMID:32814053
  title: Interactome Mapping Provides a Network of Neurodegenerative Disease Proteins and Uncovers Widespread Protein Aggregation in Affected Brains.
  findings: []
  reference_review:
    relevance: LOW
    correctness: VERIFIED
    review_notes: High-throughput interactome; incidental partners, bare protein binding.
- id: PMID:33961781
  title: Dual proteome-scale networks reveal cell-specific remodeling of the human interactome.
  findings: []
  reference_review:
    relevance: MEDIUM
    correctness: VERIFIED
    review_notes: Captures the SRP9-SRP14 interaction; bare protein binding term.
- id: PMID:34208095
  title: 'SRPassing Co-translational Targeting: The Role of the Signal Recognition Particle in Protein Targeting and mRNA Protection.'
  findings:
  - statement: SRP9 and SRP14 form the Alu domain of SRP and function in elongation arrest, positioning near the ribosomal elongation-factor binding site to pause translation; signal-sequence recognition is performed by SRP54.
    reference_section_type: OTHER
  reference_review:
    relevance: HIGH
    correctness: VERIFIED
    review_notes: Authoritative SRP review describing SRP9/14 Alu-domain elongation arrest; full text available.
- id: PMID:35271311
  title: 'OpenCell: Endogenous tagging for the cartography of human cellular organization.'
  findings: []
  reference_review:
    relevance: MEDIUM
    correctness: VERIFIED
    review_notes: Endogenous-tagging interactome; captures SRP9-SRP14 interaction, bare protein binding.
- id: PMID:40205054
  title: Multimodal cell maps as a foundation for structural and functional genomics.
  findings: []
  reference_review:
    relevance: MEDIUM
    correctness: VERIFIED
    review_notes: Cell map; captures SRP9-SRP14 interaction, bare protein binding.
- id: Reactome:R-HSA-1799332
  title: 'Reactome: Nascent polypeptide:mRNA:ribosome complex binds signal recognition particle (SRP)'
  findings: []
- id: PMID:26585389
  title: Retrotransposition and Crystal Structure of an Alu RNP in the Ribosome-Stalling Conformation.
  findings:
  - statement: 2.0 A crystal structure of the human Alu RNP (SRP9/14 bound to Alu RNA) in the ribosome-stalling conformation; SRP9/14 clamps the Alu RNA and docks at the ribosomal elongation-factor binding site, and mutations weakening the SRP9/14-RNA interface abolish Alu retrotransposition.
    reference_section_type: ABSTRACT
  reference_review:
    relevance: HIGH
    correctness: VERIFIED
    review_notes: PubMed-verified (Ahl et al., Mol Cell 2015, PDB 5AOX). Structural basis of the SRP9/14 Alu-domain RNA clamp and its ribosome-stalling geometry; also links SRP9/14 to Alu retrotransposition.
- id: PMID:37156570
  title: Nuclear SRP9/SRP14 heterodimer transcriptionally regulates 7SL and BC200 RNA expression.
  findings:
  - statement: SRP9/14 localizes substantially in the nucleus; siRNA knockdown selectively reduces the Alu-like Pol III transcripts 7SL (RN7SL1) and BC200 (BCYRN1) by decreasing Pol III occupancy at these loci rather than altering RNA stability, defining a noncanonical nuclear transcriptional role for SRP9/14.
    reference_section_type: ABSTRACT
  reference_review:
    relevance: MEDIUM
    correctness: VERIFIED
    review_notes: PubMed-verified (Gussakovsky et al., RNA 2023). Noncanonical nuclear role of the SRP9/14 heterodimer; not the core SRP/elongation-arrest function.
- id: PMID:37309897
  title: Alu RNA fold links splicing with signal recognition particle proteins.
  findings:
  - statement: SRP9/14 binds compact (closed) Alu RNA conformations and modulates inclusion of Alu-derived exons, with RNA structure (closed vs open Alu fold) predicting exon inclusion; demonstrates a noncanonical SRP9/14 role in pre-mRNA splicing regulation.
    reference_section_type: ABSTRACT
  reference_review:
    relevance: MEDIUM
    correctness: VERIFIED
    review_notes: PubMed-verified (Borovska et al., Nucleic Acids Res 2023). Noncanonical Alu-exon splicing-regulation role of SRP9/14; distinct from the core SRP function.
- id: PMID:38858088
  title: The nucleolar phase of signal recognition particle assembly.
  findings:
  - statement: SRP proteins (including SRP9/14) associate with many nucleolar and ribosome-biogenesis factors; GFP-SRP9 appears mostly nuclear with faint cytoplasmic staining, and nucleolar integrity is required for proper SRP protein localization, supporting a nucleolar phase of SRP assembly.
    reference_section_type: ABSTRACT
  reference_review:
    relevance: MEDIUM
    correctness: VERIFIED
    review_notes: PubMed-verified (Issa et al., Life Sci Alliance 2024). Supports a nucleolar SRP-assembly compartment and nuclear localization of SRP9 during biogenesis.
- id: PMID:39563162
  title: The role of SRP9/SRP14 in regulating Alu RNA.
  findings:
  - statement: Reviews SRP9/14 regulation of Alu-family RNAs (maturation, trafficking, splicing, retrotransposition, transcription); primate SRP9/14 is present at ~20-fold molar excess over assembled SRP and binds 7SL with sub-nanomolar affinity, enabling extensive extra-canonical Alu-RNA regulation.
    reference_section_type: OTHER
  reference_review:
    relevance: MEDIUM
    correctness: VERIFIED
    review_notes: PubMed-verified (Gussakovsky et al., RNA Biol 2024). Synthesis of canonical and noncanonical SRP9/14 functions.
- id: PMID:38847231
  title: 'Significance of signal recognition particle 9 nuclear translocation: implications for pancreatic cancer prognosis and functionality.'
  findings:
  - statement: In resected pancreatic cancer, higher SRP9 nuclear staining is associated with improved recurrence-free survival; SRP9 nuclear translocation is modulated by amino-acid/nutrient status.
    reference_section_type: ABSTRACT
  reference_review:
    relevance: LOW
    correctness: VERIFIED
    review_notes: PubMed-verified (Sato et al., Int J Oncol 2024). Biomarker/association-level finding; not core SRP9 molecular function.
- id: file:human/SRP9/SRP9-uniprot.txt
  title: UniProt entry P49458 (SRP9_HUMAN), Signal recognition particle 9 kDa protein
  findings:
  - statement: SRP9 is a subunit of the SRP ribonucleoprotein (7SL RNA + six proteins); with SRP14 and the Alu portion of the SRP RNA it forms the elongation-arrest domain; binds RNA as the SRP9/SRP14 heterodimer; cytoplasmic.
    reference_section_type: OTHER
core_functions:
- description: RNA-binding subunit that, as an obligate heterodimer with SRP14, binds the Alu portion of the SRP 7SL RNA to form the Alu (elongation-arrest) domain of the signal recognition particle.
  molecular_function:
    id: GO:0008312
    label: 7S RNA binding
  in_complex:
    id: GO:0005786
    label: signal recognition particle, endoplasmic reticulum targeting
  supported_by:
  - reference_id: file:human/SRP9/SRP9-uniprot.txt
    supporting_text: The complex of SRP9 and SRP14 is required for SRP
  - reference_id: PMID:34208095
    supporting_text: SRP9 and SRP14 function in elongation arrest
  - reference_id: PMID:26585389
    supporting_text: >-
      We defined a minimal Alu RNA sufficient for effective retrotransposition and determined
      a high-resolution structure of its complex with the SRP9/14 proteins.
- description: Part of the SRP Alu domain that transiently arrests translation elongation at the ribosomal elongation-factor site, pausing the nascent chain while SRP-dependent co-translational targeting delivers the ribosome to the ER membrane.
  molecular_function:
    id: GO:0008312
    label: 7S RNA binding
  in_complex:
    id: GO:0005786
    label: signal recognition particle, endoplasmic reticulum targeting
  supported_by:
  - reference_id: PMID:34208095
    supporting_text: SRP9 and SRP14 function in elongation arrest
  - reference_id: PMID:26585389
    supporting_text: >-
      The RNA adopts a compact, closed conformation that matches the envelope of the SRP Alu
      domain in the ribosomal translation elongation factor-binding site.
  directly_involved_in:
  - id: GO:0045900
    label: negative regulation of translational elongation
  - id: GO:0006614
    label: SRP-dependent cotranslational protein targeting to membrane
proposed_new_terms: []
suggested_questions:
- question: How strictly required is SRP9/SRP14-mediated elongation arrest for productive ER targeting in mammalian cells, given that some substrates may be targeted without efficient arrest?
- question: Do the Alu-RNA-binding activities of SRP9/SRP14 toward Alu-derived transcripts (scAlu/scB1) have any regulatory role distinct from canonical SRP function?
suggested_experiments:
- description: Reconstitute SRP with wild-type versus RNA-binding-deficient SRP9 to quantify the contribution of the SRP9/SRP14 Alu domain to elongation arrest and targeting efficiency on defined nascent-chain substrates.
- description: Use selective ribosome profiling in cells depleted of SRP9 to measure genome-wide effects on co-translational ER targeting and elongation pausing of signal-sequence-bearing mRNAs.

SRP9

Gene Description

Existing Annotations Review

Core Functions

RNA-binding subunit that, as an obligate heterodimer with SRP14, binds the Alu portion of the SRP 7SL RNA to form the Alu (elongation-arrest) domain of the signal recognition particle.

Part of the SRP Alu domain that transiently arrests translation elongation at the ribosomal elongation-factor site, pausing the nascent chain while SRP-dependent co-translational targeting delivers the ribosome to the ER membrane.

References

Suggested Questions for Experts

Suggested Experiments

Deep Research

Falcon

Research Report: Human SRP9 (UniProt P49458)

1. Key concepts and definitions (current understanding)

2. Recent developments and latest research (prioritizing 2023–2024)

2.1 Nuclear SRP9/14 as a Pol III transcriptional regulator (2023)

2.2 SRP9/14 in Alu-exon splicing regulation (2023)

2.3 SRP biogenesis and nucleolar coordination (2024)

2.4 Updated synthesis of SRP9/14 regulation of Alu RNAs (2024 review)

3. Current applications and real-world implementations

4. Expert opinions and analysis (authoritative interpretations)

5. Relevant statistics and data highlights

Visual evidence from primary literature

Summary

Artifacts

Citations

📚 Additional Documentation

Notes

SRP9 (P49458) review notes

Identity and overview

Core function: Alu domain / elongation arrest

Complex membership

Original characterization (PMID:7730321, abstract only)

Subcellular location

protein binding (GO:0005515, IPI) annotations

Conclusions for review actions

Falcon deep-research findings (incorporated 2026-06)

Pn Notes

SRP9 PN Consistency Notes

Source Files Checked

Deep Research Files

AIGR Review Snapshot

PN Consistency Summary

Full Consistency Review

PN Dossier Context

PN row 1: ER proteostasis | Protein transport | Signal recognition particle component

Projected GO annotations (2)

Note

📄 View Raw YAML