UniProt P10080 (locus YHL034C; canonical gene symbol SBP1) is the RGG/RRM RNA-binding protein Sbp1. SSB1 and SSBR1 are historical synonyms for this protein and must not be confused with the unrelated ribosome-associated Hsp70 chaperone Ssb1/Ssb2. Sbp1 is built from two RRM domains separated by a low-complexity RGG (Arg-Gly-Gly) box. Its core molecular function is broadly sequence-non-specific mRNA binding with a positional preference for the 5' UTR, while the PAB1 transcript contains a specifically recognized A-rich 5'-UTR tract. Sbp1 acts as a translation repressor through RGG-dependent RNA binding and assembly with Pab1/eIF4G-containing initiation complexes, although whether Sbp1 binds eIF4G directly or through RNA/Pab1 is disputed. It thereby promotes transition of mRNAs out of active translation. Sbp1 is predominantly cytoplasmic in log phase and relocalizes to P-bodies and stress granules under stress; it is a P-body disassembly factor during recovery from stress, dissolving Edc3/Dhh1/Scd6 foci in an RGG- and arginine-methylation-dependent manner. The older literature additionally reports a nucleolar, snR10/snR11-associated form, but the well-characterized contemporary function is cytoplasmic mRNP/translation control.
Definition: The disassembly of a cytoplasmic processing body (P-body), an mRNP granule containing translationally repressed mRNAs and mRNA-decay factors.
Justification: The cited experiment is specifically about P-body disassembly, but GO currently provides stress granule disassembly (GO:0035617) and P granule disassembly (GO:1903864), not a term for P-body disassembly. GO:0032984 protein-containing complex disassembly is the best available interim parent but loses the biologically important granule identity.
Supporting Evidence:
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0003729 mRNA binding | IBA GO_REF:0000033 | ACCEPT | Summary: mRNA binding is a core molecular function of Sbp1. CLIP analysis identified Sbp1 among P-body/stress-granule-associated RNA-binding proteins and showed it binds mRNAs with positional rather than strong sequence specificity, with a clear preference for the 5' UTR. The binding is mediated by its two RRM domains plus the RGG box. Reason: Core molecular function; well supported by phylogenetic inference and by direct CLIP evidence in S. cerevisiae. Supporting Evidence: file:yeast/SBP1/SBP1-deep-research-falcon.md A global yeast mRNP study using CLIP identified Sbp1 among a set of PB/SG-associated RBPs (with Pat1, Lsm1, Dhh1) and found that Sbp1 exhibits **positional specificity** on transcripts: Sbp1 binding shows a clear preference for the **5β² UTR**, rather than strong sequence specificity |
| GO:0005634 nucleus | IBA GO_REF:0000033 | KEEP AS NON CORE | Summary: Nuclear localization is phylogenetically inferred and is consistent only with the older nucleolar-form characterization of SSB1 (snR10/snR11-associated). The well-characterized contemporary function of Sbp1 is cytoplasmic; the falcon deep research synthesis does not address the historical nuclear site of action. Reason: Supported by historical immunofluorescence and phylogenetic inference, but retained as non-core because the well-characterized contemporary function is cytoplasmic. Supporting Evidence: PMID:2823109 examination of the subcellular distribution of SSB1 by immunofluorescence microscopy indicated that SSB1 is a nuclear protein, predominantly located in the nucleolus. |
| GO:0005737 cytoplasm | IBA GO_REF:0000033 | ACCEPT | Summary: Cytoplasm is the constitutive subcellular location of Sbp1, consistent with its cytoplasmic mRNP/translation-control function and phylogenetic inference. Reason: Core, constitutive localization; consistent across phylogenetic inference and direct experimental evidence. Supporting Evidence: file:yeast/SBP1/SBP1-deep-research-falcon.md Sbp1 itself is largely cytoplasmic in mid-log phase and accumulates in PBs under stress conditions (e.g., glucose deprivation/high cell density) or upon overexpression, consistent with conditional relocalization during mRNP remodeling |
| GO:1990904 ribonucleoprotein complex | IBA GO_REF:0000033 | ACCEPT | Summary: Sbp1 is a component of cytoplasmic messenger ribonucleoprotein (mRNP) complexes, consistent with its role in regulating mRNP state transitions between translation and translationally repressed/decay-competent states (P-bodies and stress granules). Reason: Supported by mRNP/CLIP studies placing Sbp1 within cytoplasmic mRNP complexes. Supporting Evidence: file:yeast/SBP1/SBP1-deep-research-falcon.md SBP1 encodes an RGG/RRM RNA-binding protein that regulates cytoplasmic mRNP state transitions. |
| GO:0000932 P-body | IEA GO_REF:0000044 | ACCEPT | Summary: Sbp1 accumulates in P-bodies under stress and upon overexpression, and is itself a P-body disassembly factor during recovery from stress. P-body localization is a genuine and functionally meaningful aspect of Sbp1 biology, though it is stress/condition-dependent rather than constitutive. Reason: Genuine, condition-dependent localization that is the site of Sbp1's core P-body disassembly function during stress recovery. Supporting Evidence: file:yeast/SBP1/SBP1-deep-research-falcon.md Sbp1 itself is largely cytoplasmic in mid-log phase and accumulates in PBs under stress conditions (e.g., glucose deprivation/high cell density) or upon overexpression, consistent with conditional relocalization during mRNP remodeling |
| GO:0003676 nucleic acid binding | IEA GO_REF:0000002 | KEEP AS NON CORE | Summary: Generic nucleic-acid binding inferred from InterPro RRM-domain signatures. The activity is correct but the more specific child terms RNA binding (GO:0003723) and especially mRNA binding (GO:0003729) / mRNA 5'-UTR binding (GO:0048027) better capture the demonstrated function. Reason: Correct but uninformatively general; superseded by more specific RNA/mRNA binding annotations. Supporting Evidence: file:yeast/SBP1/SBP1-deep-research-falcon.md describes the characteristic architecture of **two RRMs separated by an RGG box** |
| GO:0003723 RNA binding | IEA GO_REF:0000120 | ACCEPT | Summary: RNA binding is well supported by Sbp1's two-RRM-plus-RGG architecture and by direct CLIP evidence. The more specific child term mRNA binding (GO:0003729) better captures the experimentally demonstrated activity, but this parent term is also correct. Reason: Correct; the more specific mRNA binding term is preferred where supported, but RNA binding is accurate. Supporting Evidence: file:yeast/SBP1/SBP1-deep-research-falcon.md The literature synthesized here explicitly studies *Saccharomyces cerevisiae* Sbp1/Sbp1p (also referred to historically as Ssb1p) and describes the characteristic architecture of **two RRMs separated by an RGG box** |
| GO:0005730 nucleolus | IEA GO_REF:0000044 | KEEP AS NON CORE | Summary: Nucleolar localization (UniProt subcellular-location mapping) reflects the older SSB-1 characterization as a nucleolar snR10/snR11-associated protein. Distinct from the contemporary cytoplasmic mRNP/translation-control function; falcon synthesis does not address nucleolar localization. Reason: Historical nucleolar evidence separate from the well-characterized cytoplasmic function; retained as non-core. Supporting Evidence: PMID:2823109 examination of the subcellular distribution of SSB1 by immunofluorescence microscopy indicated that SSB1 is a nuclear protein, predominantly located in the nucleolus. |
| GO:0005737 cytoplasm | IEA GO_REF:0000044 | ACCEPT | Summary: Cytoplasm is the constitutive subcellular location of Sbp1, where it carries out its translation-repression function (UniProt subcellular-location mapping). Reason: Core, constitutive localization; well supported by experimental evidence. Supporting Evidence: file:yeast/SBP1/SBP1-deep-research-falcon.md Sbp1 itself is largely cytoplasmic in mid-log phase and accumulates in PBs under stress conditions (e.g., glucose deprivation/high cell density) or upon overexpression, consistent with conditional relocalization during mRNP remodeling |
| GO:0010494 cytoplasmic stress granule | IEA GO_REF:0000044 | KEEP AS NON CORE | Summary: Sbp1 localizes to both P-bodies and cytoplasmic stress granules under stress. This is a genuine but stress-conditional localization. Reason: Genuine but condition-dependent localization rather than a constitutive site of action. Supporting Evidence: PMID:23222640 Sbp1 can be contrasted to the others since it is found in both P-bodies and stress granules |
| GO:0005515 protein binding | IPI PMID:16429126 Proteome survey reveals modularity of the yeast cell machine... | MARK AS OVER ANNOTATED | Summary: Generic protein binding from a high-throughput interactome survey. The biologically meaningful protein-protein interactions of Sbp1 are captured by the specific protein-sequestering interaction with the P-body component Edc3 (GO:0140311), underlying P-body disassembly. Reason: Protein binding is uninformative; GO:0140311 captures the experimentally established competitive Edc3 interaction and its mechanistic meaning. |
| GO:0005515 protein binding | IPI PMID:16554755 Global landscape of protein complexes in the yeast Saccharom... | MARK AS OVER ANNOTATED | Summary: Generic protein binding from a high-throughput protein-complex survey. More specific protein sequestering activity toward the P-body component Edc3 (GO:0140311) captures a functionally relevant interaction. Reason: Protein binding is uninformative; GO:0140311 captures the experimentally established competitive Edc3 interaction and its mechanistic meaning. |
| GO:0005515 protein binding | IPI PMID:37968396 The social and structural architecture of the yeast protein ... | MARK AS OVER ANNOTATED | Summary: Generic protein binding from a yeast interactome study. The functionally relevant, directly established interaction is competitive binding to the P-body component Edc3 (GO:0140311), underlying P-body disassembly. Reason: Protein binding is uninformative; GO:0140311 captures the experimentally established competitive Edc3 interaction and its mechanistic meaning. |
| GO:0045947 negative regulation of translational initiation | IDA PMID:28986506 Sbp1 modulates the translation of Pab1 mRNA in a poly(A)- an... | ACCEPT | Summary: Negative regulation of translation initiation is a CORE function of Sbp1. It binds the A-rich PAB1 5' UTR and uses its RGG region to assemble an RNA-dependent repressed mRNP. Increasing Sbp1 inhibits both cap-dependent and cap-independent initiation of Pab1 mRNA. Reason: Direct experimental evidence establishes this as a core biological role of Sbp1; falcon synthesis elevates it from peripheral to core (revised from KEEP_AS_NON_CORE). Supporting Evidence: PMID:28986506 a decreased translation activity in the presence of an increasing amount of Sbp1 indicated an inhibitory function of this protein in both cap-dependent and cap-independent initiation of the Pab1 mRNA |
| GO:0045947 negative regulation of translational initiation | IMP PMID:28986506 Sbp1 modulates the translation of Pab1 mRNA in a poly(A)- an... | ACCEPT | Summary: Negative regulation of translation initiation is a CORE function of Sbp1, supported here by mutational/phenotypic (IMP) evidence (e.g. RGG- and poly(A)-dependent modulation of Pab1 mRNA translation). The full-text study supports an RNA-dependent Sbp1-Pab1-eIF4G complex rather than direct Sbp1-eIF4G binding. Reason: Core biological role supported by direct mutant phenotype evidence; revised from KEEP_AS_NON_CORE based on falcon synthesis. Supporting Evidence: PMID:28986506 Substitution of the RGG repeats with GS repeats, or methylation of arginines in the RGG repeats, abolishes the inhibitory function of Sbp1 on the Pab1 mRNA in both cap-dependent and cap-independent initiation pathways |
| GO:0045947 negative regulation of translational initiation | IDA PMID:39617253 An Intrinsically Disordered RNA Binding Protein Modulates mR... | ACCEPT | Summary: Negative regulation of translation initiation is a CORE function of Sbp1. As an intrinsically disordered RGG/RRM RNA-binding protein it modulates mRNA translation and storage, repressing initiation through 5'-UTR engagement. Reason: Core biological role; revised from KEEP_AS_NON_CORE based on falcon synthesis and direct evidence. Supporting Evidence: PMID:39617253 the binding of Sbp1 to the 5'UTRs of mRNAs represses both cap-dependent and cap-independent translation initiation of proteins |
| GO:0045947 negative regulation of translational initiation | IMP PMID:39617253 An Intrinsically Disordered RNA Binding Protein Modulates mR... | ACCEPT | Summary: Negative regulation of translation initiation is a CORE function of Sbp1, supported by mutant phenotype (IMP) evidence. Its 5'-UTR binding and RGG region are central to repression of both cap-dependent and cap-independent initiation. Reason: Core biological role supported by mutant phenotypes; revised from KEEP_AS_NON_CORE based on falcon synthesis. Supporting Evidence: PMID:39617253 the binding of Sbp1 to the 5'UTRs of mRNAs represses both cap-dependent and cap-independent translation initiation of proteins |
| GO:0048027 mRNA 5'-UTR binding | IDA PMID:28986506 Sbp1 modulates the translation of Pab1 mRNA in a poly(A)- an... | ACCEPT | Summary: A precise, core molecular function: Sbp1's two distal RRMs bind specifically and cooperatively to the poly(A)-rich sequence in the PAB1 mRNA 5' UTR. This RNA interaction is required for repression of cap-dependent and cap-independent initiation of Pab1 mRNA. Reason: Specific, experimentally supported molecular function central to Sbp1's role in translation control. Supporting Evidence: PMID:28986506 the two distal RRMs of Sbp1 bind to the poly(A) sequence in the 5'UTR of the Pab1 mRNA specifically and cooperatively |
| GO:0048027 mRNA 5'-UTR binding | IDA PMID:39617253 An Intrinsically Disordered RNA Binding Protein Modulates mR... | ACCEPT | Summary: Core molecular function: Sbp1 preferentially binds the 5' UTR of target mRNAs. The cited study links this 5'-UTR binding directly to repression of both cap-dependent and cap-independent translation initiation. Reason: Specific, experimentally supported molecular function central to Sbp1's role in translation control. Supporting Evidence: PMID:39617253 the binding of Sbp1 to the 5'UTRs of mRNAs represses both cap-dependent and cap-independent translation initiation of proteins |
| GO:0035617 stress granule disassembly | IDA PMID:35440550 Low complexity RGG-motif sequence is required for Processing... | MODIFY | Summary: Sbp1 is a granule disassembly factor during recovery from stress. Roy et al. 2022 (PMID:35440550) is explicitly about PROCESSING BODY (P-body) disassembly: the title is "Low complexity RGG-motif sequence is required for Processing body (P-body) disassembly," and all three markers tested (Edc3, Dhh1, Scd6) are P-body components. After sodium-azide stress and recovery, delta-sbp1 cells are defective in disassembly of these P-body foci, and purified Sbp1 dissolves Edc3 assemblies in vitro in an RGG- and arginine-methylation-dependent manner. The annotated term GO:0035617 is STRESS GRANULE disassembly, a distinct GO process; the evidence supports P-body disassembly. There is no specific "P-body disassembly" / "processing body disassembly" term in GO (verified via OLS), so the closest accurate available term is GO:0032984 (protein-containing complex disassembly), which captures the demonstrated disaggregation of the P-body Edc3 protein assembly. Reason: The cited evidence (Roy et al. 2022, PMID:35440550) demonstrates P-body disassembly, not stress granule disassembly; GO:0035617 (stress granule disassembly) is the wrong process. No specific P-body/processing-body disassembly term exists in GO (confirmed via OLS - searches for "P-body disassembly" and "processing body disassembly" return no GO class), so the most accurate available replacement is GO:0032984 (protein-containing complex disassembly), matching the observed dissolution of Edc3 P-body assemblies. Proposed replacements: protein-containing complex disassembly Supporting Evidence: PMID:35440550 we identify RGG-motif containing translation repressor protein Sbp1 as a disassembly factor of P-bodies since disassembly of P-bodies is defective in Ξsbp1 |
| GO:0000932 P-body | IDA PMID:23222640 Global analysis of yeast mRNPs. | ACCEPT | Summary: Direct evidence places Sbp1 among P-body/stress-granule-associated RNA-binding proteins. P-body engagement is a genuine, functionally central but stress/condition-dependent aspect of Sbp1 biology (it both localizes to and promotes disassembly of P-bodies). Reason: Genuine condition-dependent localization that is the site of Sbp1's core P-body disassembly function. Supporting Evidence: PMID:23222640 Sbp1 can be contrasted to the others since it is found in both P-bodies and stress granules |
| GO:0010494 cytoplasmic stress granule | IDA PMID:23222640 Global analysis of yeast mRNPs. | KEEP AS NON CORE | Summary: Sbp1 is found in cytoplasmic stress granules as well as P-bodies under stress. This is a genuine but stress-conditional localization. Reason: Genuine but condition-dependent localization rather than a constitutive site of action. Supporting Evidence: PMID:23222640 Sbp1 can be contrasted to the others since it is found in both P-bodies and stress granules |
| GO:0010494 cytoplasmic stress granule | HDA PMID:26777405 ATPase-Modulated Stress Granules Contain a Diverse Proteome ... | KEEP AS NON CORE | Summary: High-throughput proteomic identification of Sbp1 in stress granules, consistent with the focused microscopy showing stress-dependent Sbp1 stress-granule localization. Genuine but condition-dependent. Reason: Genuine but condition-dependent localization; consistent with focused studies. Sbp1 is identified in the study's supplementary stress-granule core proteome; the cached article body describes the proteomic assay but does not name individual supplementary-table hits. Supporting Evidence: PMID:26777405 Proteomic analysis of stress granule cores reveals a dense network of protein-protein interactions and links between stress granules and human diseases and identifies ATP-dependent helicases and protein remodelers as conserved stress granule components. |
| GO:0003729 mRNA binding | HDA PMID:23222640 Global analysis of yeast mRNPs. | ACCEPT | Summary: mRNA binding is a core molecular function, directly demonstrated by CLIP in the Mitchell et al. global mRNP analysis, which mapped Sbp1's transcriptome-wide binding with a 5'-UTR positional preference. Reason: Core molecular function with direct transcriptome-wide binding evidence. Supporting Evidence: PMID:23222640 In contrast to Lsm1 and Pat1, Sbp1 shows bias towards the 5β² UTR |
| GO:0003729 mRNA binding | IDA PMID:23222640 Global analysis of yeast mRNPs. | ACCEPT | Summary: mRNA binding is a core molecular function. Direct CLIP evidence shows Sbp1 binds mRNAs with positional (5'-UTR) rather than strong sequence specificity, mediated by its two RRMs and RGG box. Reason: Core molecular function with direct experimental support. Supporting Evidence: PMID:23222640 In contrast to Lsm1 and Pat1, Sbp1 shows bias towards the 5β² UTR |
| GO:0000932 P-body | IDA PMID:16782896 Sbp1p affects translational repression and decapping in Sacc... | ACCEPT | Summary: Foundational evidence (Segal et al. 2006) places Sbp1 in P-body biology: overexpression increases P-body size and number, whereas loss of Sbp1 reduces P-body formation. The curator's localization annotation is retained; the cached abstract does not include the microscopy details from the full paper. Reason: Genuine condition-dependent localization established in the foundational Segal 2006 study and central to Sbp1's P-body remodeling function. Supporting Evidence: PMID:16782896 Sbp1p overexpression restores normal decay rates in decapping-defective strains and increases P-body size and number. |
| GO:0005730 nucleolus | IDA PMID:2121740 SSB-1 of the yeast Saccharomyces cerevisiae is a nucleolar-s... | KEEP AS NON CORE | Summary: Nucleolar localization derives from the older characterization of "SSB-1" as a nucleolar-specific, silver-binding protein associated with the snR10 and snR11 small nuclear RNAs. This is a distinct, historical strand of evidence that the contemporary cytoplasmic mRNP/translation-control literature (and the falcon deep research synthesis) does not address. Retained as non-core pending reconciliation of the nucleolar and cytoplasmic bodies of evidence. Reason: Genuine IDA evidence from the original snRNA-association studies, but not part of the well-characterized contemporary cytoplasmic function; falcon synthesis does not address nucleolar localization. Supporting Evidence: PMID:2121740 SSB-1 colocalized with fibrillarin in a double-label immunofluorescence mapping experiment to the yeast nucleolus. |
| GO:0005730 nucleolus | IDA PMID:2823109 Saccharomyces cerevisiae SSB1 protein and its relationship t... | KEEP AS NON CORE | Summary: Nucleolar localization from the original SSB1 characterization relating it to nucleolar RNA-binding proteins. Same caveat as the snR10/snR11 study: this historical nucleolar evidence is separate from the contemporary cytoplasmic mRNP/translation-control function and is not addressed by the falcon synthesis. Reason: Genuine historical IDA evidence, but not part of the well-characterized contemporary cytoplasmic function. Supporting Evidence: PMID:2823109 examination of the subcellular distribution of SSB1 by immunofluorescence microscopy indicated that SSB1 is a nuclear protein, predominantly located in the nucleolus. |
| GO:0005737 cytoplasm | IDA PMID:16782896 Sbp1p affects translational repression and decapping in Sacc... | ACCEPT | Summary: Cytoplasm is the constitutive site of action for Sbp1. It is largely cytoplasmic in mid-log phase, where it carries out translational repression, relocalizing to P-bodies/stress granules only under stress. Reason: Core, constitutive subcellular localization where Sbp1 performs its translation-control function. Supporting Evidence: file:yeast/SBP1/SBP1-deep-research-falcon.md Sbp1 itself is largely cytoplasmic in mid-log phase and accumulates in PBs under stress conditions (e.g., glucose deprivation/high cell density) or upon overexpression, consistent with conditional relocalization during mRNP remodeling |
| GO:0017148 negative regulation of translation | IDA PMID:22284680 Scd6 targets eIF4G to repress translation: RGG motif protein... | ACCEPT | Summary: Negative regulation of translation is a CORE function. Rajyaguru et al. showed Sbp1 represses translation in an RGG-motif-dependent manner and reported an Sbp1-eIF4G interaction. A later purified-protein study found that this interaction is not direct and is instead mediated by RNA or a ternary protein. The more specific child term negative regulation of translational initiation (GO:0045947) is also annotated and preferred. Reason: Core biological role with biochemical evidence for repression; the directness of the reported Sbp1-eIF4G interaction is disputed by later purified-protein work. Supporting Evidence: PMID:22284680 Npl3 and Sbp1, also directly bind eIF4G and repress translation in a manner dependent on their RGG motifs PMID:28986506 Using purified RNA-free proteins, we observed no direct interactions between eIF4G1 and Sbp1, and between eIF4G1 and the RGG domain of Sbp1 (Sbp1RGG) |
| GO:0031370 eukaryotic initiation factor 4G binding | IDA PMID:22284680 Scd6 targets eIF4G to repress translation: RGG motif protein... | ACCEPT | Summary: Rajyaguru et al. reported RGG-dependent Sbp1-eIF4G binding by GST pulldown. Later experiments with purified RNA-free proteins detected no direct interaction and concluded that the earlier association was likely mediated by endogenous RNA or a ternary protein. The curator's IDA annotation is retained, but direct binding is explicitly disputed. Reason: Retain the curator's specific interaction annotation because the original study reported RGG-dependent binding, while recording the later contradictory purified-protein result rather than presenting direct binding as settled. Supporting Evidence: PMID:22284680 Npl3 and Sbp1, also directly bind eIF4G and repress translation in a manner dependent on their RGG motifs PMID:28986506 Using purified RNA-free proteins, we observed no direct interactions between eIF4G1 and Sbp1, and between eIF4G1 and the RGG domain of Sbp1 (Sbp1RGG) |
| GO:0140311 protein sequestering activity | IDA PMID:35440550 Low complexity RGG-motif sequence is required for Processing... | NEW | Summary: NEW annotation capturing the molecular basis of Sbp1's P-body disassembly activity. Roy et al. 2022 (PMID:35440550) showed by binding studies with purified proteins that Sbp1 physically interacts with Edc3 and that the Sbp1-Edc3 interaction COMPETES with Edc3-Edc3 self-association; addition of purified Sbp1 (but not the RGG-deletion mutant) significantly decreases Edc3 assemblies. By binding Edc3 to prevent it from interacting with its self-assembly partners, Sbp1 exhibits protein sequestering activity, which is mechanistically distinct from its mRNA-binding/translation-repression functions. This term supersedes the generic protein binding (GO:0005515) annotations for the Edc3 interaction. Reason: Specific, informative MF whose definition covers binding a protein to prevent its interaction with other partners. That matches the observed competition between Sbp1-Edc3 and Edc3-Edc3 binding and captures the RNA-independent disruption activity underlying P-body disassembly. The separate GO:0032984 replacement and proposed P-body-disassembly term capture the dissolution of existing assemblies that this MF does not fully express; GO:0140311 replaces uninformative protein binding for the competitive interaction itself. Supporting Evidence: PMID:35440550 Binding studies using purified proteins revealed that Sbp1 physically interacts with Edc3 and Sbp1-Edc3 interaction competes with Edc3-Edc3 interaction |
| GO:0032055 negative regulation of translation in response to stress | IMP PMID:16782896 Sbp1p affects translational repression and decapping in Sacc... | KEEP AS NON CORE | Summary: Sbp1 represses translation and promotes P-body engagement particularly under stress conditions (e.g. glucose deprivation), consistent with a stress-responsive translational-repression role. This is a more contextualized child of the core negative-regulation-of-translation function. Reason: Valid stress-contextualized refinement of the core translational-repression role; kept as non-core relative to the general repression function. Supporting Evidence: PMID:16782896 Sbp1p promotes translational repression of mRNA during glucose deprivation |
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Download this section (compressed HTML)Q: Does Sbp1 disassemble P-bodies primarily by sequestering Edc3 from Edc3-Edc3 contacts, or does it also remodel RNA and other P-body scaffold interactions?
Q: How are Sbp1's historical nucleolar association with snR10/snR11 and its contemporary cytoplasmic translation-control functions partitioned across growth conditions?
Experiment: Compare P-body disassembly kinetics after stress recovery in strains expressing separation-of-function Sbp1 variants that disrupt the RRM domains, the RGG motif, or mapped Edc3-contact surfaces, using endogenous Edc3/Dhh1/Scd6 markers.
Hypothesis: Sbp1's Edc3-binding activity is sufficient to drive P-body dissolution independently of its mRNA-binding activity.
Type: live-cell imaging and separation-of-function mutagenesis
Experiment: Quantify endogenously tagged Sbp1 together with nucleolar, P-body, and stress-granule markers across logarithmic growth, glucose deprivation, and recovery, and pair the imaging with snR10/snR11 and mRNA interaction measurements.
Hypothesis: The nucleolar and cytoplasmic pools of Sbp1 represent regulated, condition-specific functions rather than conflicting localization assignments.
Type: quantitative microscopy and RNA co-immunoprecipitation
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