YAR1 encodes an ankyrin repeat protein that functions as a dedicated chaperone for the small ribosomal subunit protein Rps3. Yar1 binds newly synthesized Rps3, prevents Rps3 aggregation, supports its solubility and nuclear delivery, and thereby promotes small ribosomal subunit biogenesis and export. The conserved ankyrin-repeat/PANTHER family context explains domain architecture but does not support transferred MBF/SBF transcription-complex annotations for yeast Yar1.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
|
GO:0001228
DNA-binding transcription activator activity, RNA polymerase II-specific
|
IBA
GO_REF:0000033 |
REMOVE |
Summary: The IBA transcription-activator annotation is not supported for yeast Yar1.
Reason: The direct literature establishes Yar1 as an Rps3-specific ribosomal-protein chaperone, not as a DNA-binding transcription activator; this appears to be an inappropriate family transfer.
Supporting Evidence:
PMID:22570489
Yar1 directly interacts with the small ribosomal subunit protein Rps3 and accompanies newly synthesized Rps3 from the cytoplasm into the nucleus.
|
|
GO:0045944
positive regulation of transcription by RNA polymerase II
|
IBA
GO_REF:0000033 |
REMOVE |
Summary: Positive regulation of RNA polymerase II transcription is not supported as a direct Yar1 function.
Reason: Yar1's experimentally supported role is Rps3 chaperoning and 40S biogenesis; the transcription regulation annotation is inconsistent with the yeast evidence.
|
|
GO:0030907
MBF transcription complex
|
IBA
GO_REF:0000033 |
REMOVE |
Summary: MBF transcription complex membership is not supported for yeast Yar1.
Reason: The PANTHER ankyrin-repeat family is broad and does not justify transferring MBF complex membership to Yar1; yeast evidence supports Rps3 binding instead.
Supporting Evidence:
file:interpro/panther/PTHR24198/PTHR24198-metadata.yaml
PTHR24198 is a broad ankyrin repeat domain-containing protein family rather than a Yar1-specific transcription complex family.
|
|
GO:0033309
SBF transcription complex
|
IBA
GO_REF:0000033 |
REMOVE |
Summary: SBF transcription complex membership is not supported for yeast Yar1.
Reason: The experimentally supported Yar1 function is as a dedicated Rps3 chaperone in ribosome biogenesis, not as an SBF subunit.
|
|
GO:0005515
protein binding
|
IPI
PMID:15611164 Genetic and biochemical interactions among Yar1, Ltv1 and Rp... |
MARK AS OVER ANNOTATED |
Summary: Generic protein binding is uninformative for Yar1.
Reason: PMID:15611164 supports a specific Yar1-Rps3/Ltv1 ribosome-biogenesis context; the generic protein binding term should not replace the more informative chaperone and ribosome-biogenesis annotations.
|
|
GO:0005515
protein binding
|
IPI
PMID:37968396 The social and structural architecture of the yeast protein ... |
MARK AS OVER ANNOTATED |
Summary: Interactome-derived protein binding is too generic to retain as core.
Reason: The core molecular role is Rps3-specific chaperoning, not undifferentiated protein binding from a broad interactome.
|
|
GO:0051082
unfolded protein binding
|
IDA
PMID:26112308 Co-translational capturing of nascent ribosomal proteins by ... |
MODIFY |
Summary: Yar1 acts as a dedicated protein-carrier chaperone for Rps3, so the broader term should be replaced.
Reason: Yar1 protects Rps3 from aggregation and keeps it soluble before pre-ribosome incorporation; GO:0140597 captures this carrier-chaperone role better than generic unfolded-protein binding.
Proposed replacements:
protein carrier chaperone
Supporting Evidence:
PMID:22570489
Yar1 protects Rps3 from aggregation in vitro and increases its solubility in vivo.
file:yeast/YAR1/YAR1-deep-research-falcon.md
Falcon synthesis supports Yar1 as a dedicated Rps3 carrier chaperone rather than a general unfolded-protein binding factor.
|
|
GO:0005737
cytoplasm
|
HDA
PMID:14562095 Global analysis of protein localization in budding yeast. |
ACCEPT |
Summary: Cytoplasmic localization is consistent with Yar1's interaction with newly synthesized Rps3.
Reason: Yar1 binds nascent Rps3 in the cytoplasm before accompanying it to the nuclear pre-ribosome assembly site.
|
|
GO:0000056
ribosomal small subunit export from nucleus
|
IMP
PMID:22570489 Yar1 protects the ribosomal protein Rps3 from aggregation. |
ACCEPT |
Summary: Yar1 supports small-subunit export indirectly through Rps3 maturation and pre-40S biogenesis.
Reason: yar1 deletion phenocopies ltv1 deletion with a small-subunit export defect; because Yar1 acts upstream by stabilizing Rps3, the BP annotation is retained.
Supporting Evidence:
PMID:22570489
A yar1 deletion strain displays a similar phenotype as an rps3 mutant strain, showing an accumulation of 20S pre-rRNA and a 40S export defect.
|
|
GO:0000056
ribosomal small subunit export from nucleus
|
IGI
PMID:22570489 Yar1 protects the ribosomal protein Rps3 from aggregation. |
ACCEPT |
Summary: Genetic interaction evidence supports a Yar1 contribution to 40S export.
Reason: The export phenotype follows from defective Rps3 handling and 40S maturation, so this is valid but downstream of Yar1's chaperone activity.
|
|
GO:0005634
nucleus
|
IDA
PMID:22570489 Yar1 protects the ribosomal protein Rps3 from aggregation. |
ACCEPT |
Summary: Yar1 accompanies Rps3 into the nucleus during pre-ribosome assembly.
Reason: Direct microscopy/biochemical evidence shows Yar1 travels with newly synthesized Rps3 from cytoplasm into the nucleus.
Supporting Evidence:
PMID:22570489
Yar1 directly interacts with the small ribosomal subunit protein Rps3 and accompanies newly synthesized Rps3 from the cytoplasm into the nucleus.
|
|
GO:0005634
nucleus
|
IGI
PMID:22570489 Yar1 protects the ribosomal protein Rps3 from aggregation. |
ACCEPT |
Summary: Nuclear localization is consistent with Yar1's Rps3 delivery route.
Reason: Yar1 escorts Rps3 to the nuclear pre-ribosome assembly compartment.
|
|
GO:0006970
response to osmotic stress
|
IMP
PMID:15611164 Genetic and biochemical interactions among Yar1, Ltv1 and Rp... |
KEEP AS NON CORE |
Summary: Osmotic-stress phenotypes are secondary to Yar1's ribosome-biogenesis role.
Reason: PMID:15611164 links yar1 deletion to environmental stress sensitivity, but the mechanistic basis is ribosome biogenesis and Rps3 handling rather than a dedicated stress-response function.
|
|
GO:0032880
regulation of protein localization
|
IMP
PMID:22570489 Yar1 protects the ribosomal protein Rps3 from aggregation. |
ACCEPT |
Summary: Yar1 regulates Rps3 localization by keeping Rps3 soluble and escorting it to the nucleus.
Reason: The term captures Yar1's direct effect on Rps3 localization before pre-40S assembly.
Supporting Evidence:
PMID:22570489
Yar1 directly interacts with the small ribosomal subunit protein Rps3 and accompanies newly synthesized Rps3 from the cytoplasm into the nucleus.
|
|
GO:0032880
regulation of protein localization
|
IPI
PMID:22570489 Yar1 protects the ribosomal protein Rps3 from aggregation. |
ACCEPT |
Summary: Protein-localization regulation is supported by Yar1-Rps3 interaction evidence.
Reason: Yar1 binding promotes productive Rps3 delivery and suppresses defects caused by yar1 deletion.
|
|
GO:0034599
cellular response to oxidative stress
|
IMP
PMID:15611164 Genetic and biochemical interactions among Yar1, Ltv1 and Rp... |
KEEP AS NON CORE |
Summary: Oxidative-stress phenotypes are retained as non-core.
Reason: Stress sensitivity is experimentally observed in yar1 mutants, but available evidence points to ribosome biogenesis defects as the core molecular basis.
|
|
GO:0042274
ribosomal small subunit biogenesis
|
IMP
PMID:15611164 Genetic and biochemical interactions among Yar1, Ltv1 and Rp... |
ACCEPT |
Summary: Ribosomal small subunit biogenesis is a core Yar1 biological role.
Reason: Yar1 acts through Rps3, a 40S subunit protein; yar1 deletion causes ribosome-biogenesis defects that are suppressed by RPS3 overexpression.
Supporting Evidence:
PMID:15611164
Overexpression of RPS3 suppresses both the stress sensitivity and the ribosome biogenesis defect of Deltayar1.
|
|
GO:0042274
ribosomal small subunit biogenesis
|
IGI
PMID:15611164 Genetic and biochemical interactions among Yar1, Ltv1 and Rp... |
ACCEPT |
Summary: Genetic interaction evidence supports Yar1 function in 40S biogenesis.
Reason: Yar1, Ltv1, and Rps3 interactions define a pathway connecting Rps3 handling to small ribosomal subunit production.
|
|
GO:0051082
unfolded protein binding
|
IMP
PMID:22570489 Yar1 protects the ribosomal protein Rps3 from aggregation. |
MODIFY |
Summary: Yar1's substrate binding is a specific carrier-chaperone function for Rps3.
Reason: The replacement term GO:0140597 reflects Yar1's dedicated role in binding and carrying nascent Rps3 to prevent aggregation.
Proposed replacements:
protein carrier chaperone
Supporting Evidence:
PMID:26112308
Affinity purification of four chaperones (Rrb1, Syo1, Sqt1 and Yar1) selectively enriched the mRNAs encoding their specific ribosomal protein clients.
|
Q: Should yeast Yar1 annotations explicitly distinguish Rps3 carrier-chaperone activity from downstream 40S export phenotypes?
Experiment: Test whether point mutations that disrupt the Yar1-Rps3 interface abolish Rps3 solubility and nuclear delivery without broadly altering stress-response pathways.
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organism: yeast
gene_id: YAR1
gene_symbol: YAR1
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protein_description: 'RecName: Full=Ankyrin repeat-containing protein YAR1;'
gene_info: Name=YAR1; OrderedLocusNames=YPL239W;
organism_full: Saccharomyces cerevisiae (strain ATCC 204508 / S288c) (Baker's yeast).
protein_family: Not specified in UniProt
protein_domains: Ankyrin_rpt. (IPR002110); Ankyrin_rpt-contain_sf. (IPR036770);
Ank_2 (PF12796)
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BEFORE YOU BEGIN RESEARCH: You MUST verify you are researching the CORRECT gene/protein. Gene symbols can be ambiguous, especially for less well-characterized genes from non-model organisms.
DO NOT PROCEED WITH RESEARCH ON A DIFFERENT GENE. Instead:
- State clearly: "The gene symbol 'YAR1' is ambiguous or literature is limited for this specific protein"
- Explain what you found (e.g., "Found extensive literature on a different gene with the same symbol in a different organism")
- Describe the protein based ONLY on the UniProt information provided above
- Suggest that the protein function can be inferred from domain/family information
Please provide a comprehensive research report on the gene YAR1 (gene ID: YAR1, UniProt: P46683) in yeast.
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.
Question: You are an expert researcher providing comprehensive, well-cited information.
Provide detailed information focusing on:
1. Key concepts and definitions with current understanding
2. Recent developments and latest research (prioritize 2023-2024 sources)
3. Current applications and real-world implementations
4. Expert opinions and analysis from authoritative sources
5. Relevant statistics and data from recent studies
Format as a comprehensive research report with proper citations. Include URLs and publication dates where available.
Always prioritize recent, authoritative sources and provide specific citations for all major claims.
BEFORE YOU BEGIN RESEARCH: You MUST verify you are researching the CORRECT gene/protein. Gene symbols can be ambiguous, especially for less well-characterized genes from non-model organisms.
DO NOT PROCEED WITH RESEARCH ON A DIFFERENT GENE. Instead:
- State clearly: "The gene symbol 'YAR1' is ambiguous or literature is limited for this specific protein"
- Explain what you found (e.g., "Found extensive literature on a different gene with the same symbol in a different organism")
- Describe the protein based ONLY on the UniProt information provided above
- Suggest that the protein function can be inferred from domain/family information
Please provide a comprehensive research report on the gene YAR1 (gene ID: YAR1, UniProt: P46683) in yeast.
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.
The gene/protein reviewed here is YAR1 / YPL239W from Saccharomyces cerevisiae strain S288c, matching UniProt accession P46683 and the protein name “Ankyrin repeat-containing protein Yar1”. Primary yeast studies explicitly refer to Yar1 as an ankyrin-repeat protein and experimentally connect it to ribosomal protein Rps3 (uS3) as its dedicated chaperone, aligning with the UniProt description and expected ankyrin-repeat domain function (protein–protein interaction) (koch2012yar1protectsthe pages 1-2, koch2012yar1protectsthe pages 1-1, pillet2017holdonto pages 3-4).
A central concept for YAR1 is the class of “dedicated chaperones”: specialized factors that bind a specific ribosomal protein (r-protein) to prevent its aggregation/misinteraction and to promote proper delivery to the ribosome assembly pathway. Reviews cite Yar1 as a canonical dedicated chaperone for Rps3/uS3, binding the Rps3 N-terminus (aa ~14–29) (pillet2017holdonto pages 3-4).
Yar1 is not an enzyme and no catalytic reaction has been assigned in the cited primary literature; rather, it is best understood as an anti-aggregation, escort-type chaperone whose function is implemented by direct binding to its client ribosomal protein Rps3 (koch2012yar1protectsthe pages 1-2, koch2012yar1protectsthe pages 2-3).
Direct Yar1–Rps3 binding is supported by in vivo affinity purification (near-stoichiometric co-purification) and in vitro complex formation (co-expression/co-elution), consistent with a dedicated chaperone–client relationship (koch2012yar1protectsthe pages 2-3, koch2012yar1protectsthe pages 3-4). Yar1 increases Rps3 solubility and prevents Rps3 aggregation in vitro and in vivo, including experiments where Rps3 is largely insoluble unless Yar1 is present/co-expressed (koch2012yar1protectsthe pages 8-9, koch2012yar1protectsthe pages 2-3, koch2012yar1protectsthe pages 7-8). Mechanistically, an “RNA-mimic/shielding” interpretation has been proposed based on charge complementarity: Rps3 is highly basic while Yar1 is acidic, consistent with shielding basic rRNA-binding surfaces from aberrant interactions (koch2012yar1protectsthe pages 8-9).
A 2015 Nature Communications study tested the general hypothesis that dedicated r-protein chaperones capture their clients co-translationally. In that work, affinity purification of Yar1 enriched the mRNA encoding its client Rps3, supporting co-translational association of Yar1 with nascent Rps3 (publication date: 2015-06-26; URL: https://doi.org/10.1038/ncomms8494) (pausch2015cotranslationalcapturingof pages 1-2).
A 2016 Scientific Reports paper provides a detailed model for nuclear import of Rps3 together with Yar1. Key points:
The key biochemical evidence for importin competition and the co-import model is shown in figures from this paper (mitterer2016nuclearimportof media 8e76864a, mitterer2016nuclearimportof media 4e812712).
Steady-state localization of Yar1 is predominantly cytoplasmic, with evidence that Yar1 transiently enters the nucleus and is exported via Xpo1/CRM1 (based on nuclear accumulation upon Xpo1 inhibition). Because no Yar1 NLS was identified whereas Rps3’s N-terminus acts as an NLS, Yar1 is inferred to piggyback with Rps3 into the nucleus (koch2012yar1protectsthe pages 4-6, koch2012yar1protectsthe pages 3-4).
Loss of YAR1 produces clear 40S ribosome biogenesis/maturation phenotypes. Yar1 acts upstream of Rps3 incorporation by ensuring a soluble supply of Rps3 for assembly. Consistent phenotypes reported include:
A 2004 Genetics paper reported that Yar1 physically and genetically interacts with Rps3 and functionally relates to the 40S biogenesis factor Ltv1, with both yar1 and ltv1 mutants showing 40S production defects and stress-sensitive phenotypes (publication date: 2004-12; URL: https://doi.org/10.1534/genetics.104.032656) (loar2004geneticandbiochemical pages 8-9, loar2004geneticandbiochemical pages 9-11). Importantly, RPS3 overexpression suppresses yar1 mutant phenotypes, supporting a model where Yar1’s key role is maintaining Rps3 function/availability (loar2004geneticandbiochemical pages 8-9, loar2004geneticandbiochemical pages 9-11).
YAR1 is non-essential, but yar1Δ cells show slow growth, particularly at lower temperature, and phenotypes similar to compromised Rps3 function; combining yar1Δ with defective rps3 alleles can produce stronger defects including synthetic sickness/lethality (koch2012yar1protectsthe pages 4-6, koch2012yar1protectsthe pages 6-7).
A 2023 Molecular Cell study discovered a chaperone-directed ribosome repair mechanism in yeast for oxidatively damaged ribosomal proteins (notably Tsr2/Rps26). In that context, the authors report that chaperone-dependent release was specific to Tsr2/Rps26, because neither Rps2 nor Rps3 were released by their chaperones (Tsr4 and Yar1, respectively). Additionally, H2O2 exposure increased ribosome association for Tsr2 but not for Yar1, supporting that Yar1 is not acting as the cognate “release/repair” factor for oxidized Rps3 in the tested system (publication date: 2023-05; URL: https://doi.org/10.1016/j.molcel.2023.03.030) (yang2023chaperonedirectedribosomerepair pages 5-7).
A 2024 Annual Review of Cell and Developmental Biology review synthesizes progress in ribosome assembly and repair and frames dedicated r-protein chaperones (including the Rps3 system) as part of broader ribosome homeostasis (publication date: 2024-10; URL: https://doi.org/10.1146/annurev-cellbio-111822-113326) (yang2024ribosomeassemblyand pages 8-9). A 2024 Biomolecules review focusing on the 40S “beak” region also discusses Rps3/uS3-centric pathways (including quality control and collision signaling at/near uS3) and notes the role of Yar1 in the assembly context (publication date: 2024-07; URL: https://doi.org/10.3390/biom14070882) (martinvillanueva2024thebeakof pages 10-11).
Overall, the 2023–2024 literature primarily extends context (ribosome repair and quality control; assembly–stress interfaces) rather than redefining Yar1’s core, best-supported role as the dedicated chaperone for Rps3 (yang2024ribosomeassemblyand pages 8-9, yang2023chaperonedirectedribosomerepair pages 5-7).
YAR1 is widely used as a model factor to study:
No Yar1-specific industrial or therapeutic application was identified in the retrieved evidence; its “real-world” impact is primarily as an experimentally tractable paradigm for eukaryotic ribosome biogenesis and proteostasis (pillet2017holdonto pages 3-4, yang2024ribosomeassemblyand pages 8-9).
The most consistent expert-level synthesis across primary and review sources is that Yar1’s primary, evolutionarily motivated job is to shield the aggregation-prone, basic N-terminal region of Rps3/uS3 from nonspecific interactions until it is safely delivered for 40S assembly (koch2012yar1protectsthe pages 1-2, pillet2017holdonto pages 3-4). The 2016 mechanistic import model further suggests that Yar1’s function is integrated into nucleocytoplasmic transport by an elegant “division of labor” on an Rps3 dimer: one N-domain protected by Yar1 while the other is engaged by Kap60 for import, enabling both protection and transport (mitterer2016nuclearimportof pages 2-4, mitterer2016nuclearimportof media 4e812712).
The following table consolidates key findings (function, partners, localization, phenotypes, quantitative data, and 2023–2024 context) with publication dates and URLs.
| Aspect | Concise finding | Key evidence type | Citations with URLs and publication dates |
|---|---|---|---|
| identity/domains | Verified target is YAR1 / YPL239W / UniProt P46683 from Saccharomyces cerevisiae S288c; literature consistently describes Yar1 as an ankyrin-repeat-containing protein and a dedicated chaperone for ribosomal protein Rps3/uS3. Reviews note ankyrin-repeat architecture; primary studies identify direct Rps3 binding. (koch2012yar1protectsthe pages 1-1, pillet2017holdonto pages 3-4) | biochem, review | Koch et al., J Biol Chem (2012-06), https://doi.org/10.1074/jbc.m112.365791; Pillet et al., BioEssays (2017-01), https://doi.org/10.1002/bies.201600153 |
| molecular function | Yar1’s primary function is not enzymatic; it acts as a dedicated anti-aggregation chaperone for newly synthesized Rps3, maintaining Rps3 solubility until incorporation into pre-40S particles. Direct binding occurs with free, non-ribosome-bound Rps3. (koch2012yar1protectsthe pages 1-2, koch2012yar1protectsthe pages 1-1, koch2012yar1protectsthe pages 2-3) | biochem, genetics | Koch et al., J Biol Chem (2012-06), https://doi.org/10.1074/jbc.m112.365791 |
| binding partners | Best-supported binding partner is Rps3/uS3; Yar1 binds the N-terminal region of Rps3 (aa 14–29). In vivo complexes can also include Kap60/importin-α and Kap95/importin-β bound to dimeric Rps3/Yar1 assemblies during import. Earlier genetics also linked Yar1 functionally to Ltv1. (pausch2015cotranslationalcapturingof pages 1-2, mitterer2016nuclearimportof pages 1-2, mitterer2016nuclearimportof pages 2-4, loar2004geneticandbiochemical pages 8-9) | biochem, cell bio, genetics | Pausch et al., Nat Commun (2015-06-26), https://doi.org/10.1038/ncomms8494; Mitterer et al., Sci Rep (2016-11), https://doi.org/10.1038/srep36714; Loar et al., Genetics (2004-12), https://doi.org/10.1534/genetics.104.032656 |
| mechanism | Current model: Yar1 captures nascent Rps3 co-translationally, binds its N-domain, and protects the basic rRNA-binding region from aggregation. Rps3 contains an N-terminal monopartite NLS (7-KKRK-10) adjacent to the Yar1-binding site; Kap60/Kap95 mediate major nuclear import. Kap60 and Yar1 compete for the same Rps3 N-domain, but in vivo a ternary Rps3/Rps3/Yar1/Kap60/Kap95 import configuration can form because Rps3 is dimeric. (pausch2015cotranslationalcapturingof pages 1-2, mitterer2016nuclearimportof pages 1-2, mitterer2016nuclearimportof pages 2-4, mitterer2016nuclearimportof pages 4-5) | biochem, cell bio, review | Pausch et al., Nat Commun (2015-06-26), https://doi.org/10.1038/ncomms8494; Mitterer et al., Sci Rep (2016-11), https://doi.org/10.1038/srep36714 |
| localization | Yar1 is predominantly cytoplasmic at steady state but transiently enters the nucleus; nuclear accumulation after Xpo1/CRM1 export inhibition supports a shuttling role. Yar1 likely piggybacks into the nucleus with Rps3 because no Yar1 NLS was identified, whereas Rps3 has a functional NLS. (koch2012yar1protectsthe pages 4-6, koch2012yar1protectsthe pages 3-4, koch2012yar1protectsthe pages 8-9) | cell bio, biochem | Koch et al., J Biol Chem (2012-06), https://doi.org/10.1074/jbc.m112.365791 |
| phenotypes | YAR1 is nonessential, but deletion causes slow growth (especially at low temperature), 40S biogenesis defects, 20S pre-rRNA accumulation, 40S export defects, reduced 40S peak with excess free 60S, and fewer polysomes. RPS3 overexpression suppresses many yar1Δ phenotypes; combining yar1 defects with mutant rps3 alleles enhances phenotypes or causes synthetic lethality. (koch2012yar1protectsthe pages 4-6, koch2012yar1protectsthe pages 6-7, koch2012yar1protectsthe pages 1-1, loar2004geneticandbiochemical pages 9-11) | genetics, cell bio | Koch et al., J Biol Chem (2012-06), https://doi.org/10.1074/jbc.m112.365791; Loar et al., Genetics (2004-12), https://doi.org/10.1534/genetics.104.032656 |
| quantitative stats | Recent and foundational sources provide several useful numbers: yeast makes about ~2,000 ribosomes/min and therefore >160,000 ribosomal proteins/min in rapid growth; Yar1 binds Rps3 region aa 14–29; Rps3 NLS is aa 7–10 (KKRK); in vitro anti-aggregation assays used 20-fold excess Yar1 and 200,000 g centrifugation; yar1/ltv1 mutants show an approximately ~50% decrease in 40S:60S ratio relative to WT in early work. (pausch2015cotranslationalcapturingof pages 1-2, mitterer2016nuclearimportof pages 1-2, koch2012yar1protectsthe pages 2-3, loar2004geneticandbiochemical pages 9-11) | biochem, genetics, review | Pausch et al., Nat Commun (2015-06-26), https://doi.org/10.1038/ncomms8494; Mitterer et al., Sci Rep (2016-11), https://doi.org/10.1038/srep36714; Loar et al., Genetics (2004-12), https://doi.org/10.1534/genetics.104.032656; Koch et al., J Biol Chem (2012-06), https://doi.org/10.1074/jbc.m112.365791 |
| recent developments 2023-2024 | No major 2023–2024 primary study appears to redefine Yar1’s core function beyond Rps3 chaperoning/import. However, newer work places Yar1 in broader ribosome homeostasis context: importins can bind nascent cargo co-translationally in yeast proteostasis networks; 2023 ribosome-repair work found Yar1 does not release Rps3 from oxidized ribosomes, unlike Tsr2-Rps26, arguing Yar1 is not currently supported as a ribosome-repair factor; 2024 reviews continue to cite Yar1 as the canonical Rps3 chaperone in small-subunit assembly. (yang2023chaperonedirectedribosomerepair pages 5-7, yang2024ribosomeassemblyand pages 8-9, martinvillanueva2024thebeakof pages 10-11) | primary, review | Yang et al., Mol Cell (2023-05), https://doi.org/10.1016/j.molcel.2023.03.030; Yang & Karbstein, Annu Rev Cell Dev Biol (2024-10), https://doi.org/10.1146/annurev-cellbio-111822-113326; Martín-Villanueva et al., Biomolecules (2024-07), https://doi.org/10.3390/biom14070882 |
| applications | YAR1 is mainly used as a model dedicated ribosomal-protein chaperone for studying ribosome biogenesis, proteostasis, co-translational chaperoning, and nuclear import coordination. It is also a useful genetic tool to probe 40S assembly and stress-linked ribosome homeostasis, but there are no direct translational/industrial applications specific to YAR1 established in the cited literature. (pillet2017holdonto pages 3-4, yang2024ribosomeassemblyand pages 8-9, martinvillanueva2024thebeakof pages 10-11) | review, genetics | Pillet et al., BioEssays (2017-01), https://doi.org/10.1002/bies.201600153; Yang & Karbstein, Annu Rev Cell Dev Biol (2024-10), https://doi.org/10.1146/annurev-cellbio-111822-113326; Martín-Villanueva et al., Biomolecules (2024-07), https://doi.org/10.3390/biom14070882 |
Table: This table summarizes the most relevant evidence for the identity, function, mechanism, localization, phenotypes, and recent literature context of S. cerevisiae YAR1 (P46683/YPL239W). It is designed as a compact, citation-ready reference for the final research report.
References
(koch2012yar1protectsthe pages 1-2): Barbara Koch, Valentin Mitterer, Johannes Niederhauser, Tamsyn Stanborough, Guillaume Murat, Gerald Rechberger, Helmut Bergler, Dieter Kressler, and Brigitte Pertschy. Yar1 protects the ribosomal protein rps3 from aggregation. Journal of Biological Chemistry, 287:21806-21815, Jun 2012. URL: https://doi.org/10.1074/jbc.m112.365791, doi:10.1074/jbc.m112.365791. This article has 78 citations and is from a domain leading peer-reviewed journal.
(koch2012yar1protectsthe pages 1-1): Barbara Koch, Valentin Mitterer, Johannes Niederhauser, Tamsyn Stanborough, Guillaume Murat, Gerald Rechberger, Helmut Bergler, Dieter Kressler, and Brigitte Pertschy. Yar1 protects the ribosomal protein rps3 from aggregation. Journal of Biological Chemistry, 287:21806-21815, Jun 2012. URL: https://doi.org/10.1074/jbc.m112.365791, doi:10.1074/jbc.m112.365791. This article has 78 citations and is from a domain leading peer-reviewed journal.
(pillet2017holdonto pages 3-4): Benjamin Pillet, Valentin Mitterer, Dieter Kressler, and Brigitte Pertschy. Hold on to your friends: dedicated chaperones of ribosomal proteins. BioEssays, 39:1-12, Jan 2017. URL: https://doi.org/10.1002/bies.201600153, doi:10.1002/bies.201600153. This article has 93 citations and is from a peer-reviewed journal.
(koch2012yar1protectsthe pages 2-3): Barbara Koch, Valentin Mitterer, Johannes Niederhauser, Tamsyn Stanborough, Guillaume Murat, Gerald Rechberger, Helmut Bergler, Dieter Kressler, and Brigitte Pertschy. Yar1 protects the ribosomal protein rps3 from aggregation. Journal of Biological Chemistry, 287:21806-21815, Jun 2012. URL: https://doi.org/10.1074/jbc.m112.365791, doi:10.1074/jbc.m112.365791. This article has 78 citations and is from a domain leading peer-reviewed journal.
(koch2012yar1protectsthe pages 3-4): Barbara Koch, Valentin Mitterer, Johannes Niederhauser, Tamsyn Stanborough, Guillaume Murat, Gerald Rechberger, Helmut Bergler, Dieter Kressler, and Brigitte Pertschy. Yar1 protects the ribosomal protein rps3 from aggregation. Journal of Biological Chemistry, 287:21806-21815, Jun 2012. URL: https://doi.org/10.1074/jbc.m112.365791, doi:10.1074/jbc.m112.365791. This article has 78 citations and is from a domain leading peer-reviewed journal.
(koch2012yar1protectsthe pages 8-9): Barbara Koch, Valentin Mitterer, Johannes Niederhauser, Tamsyn Stanborough, Guillaume Murat, Gerald Rechberger, Helmut Bergler, Dieter Kressler, and Brigitte Pertschy. Yar1 protects the ribosomal protein rps3 from aggregation. Journal of Biological Chemistry, 287:21806-21815, Jun 2012. URL: https://doi.org/10.1074/jbc.m112.365791, doi:10.1074/jbc.m112.365791. This article has 78 citations and is from a domain leading peer-reviewed journal.
(koch2012yar1protectsthe pages 7-8): Barbara Koch, Valentin Mitterer, Johannes Niederhauser, Tamsyn Stanborough, Guillaume Murat, Gerald Rechberger, Helmut Bergler, Dieter Kressler, and Brigitte Pertschy. Yar1 protects the ribosomal protein rps3 from aggregation. Journal of Biological Chemistry, 287:21806-21815, Jun 2012. URL: https://doi.org/10.1074/jbc.m112.365791, doi:10.1074/jbc.m112.365791. This article has 78 citations and is from a domain leading peer-reviewed journal.
(pausch2015cotranslationalcapturingof pages 1-2): Patrick Pausch, Ujjwala Singh, Yasar Luqman Ahmed, Benjamin Pillet, Guillaume Murat, Florian Altegoer, Gunter Stier, Matthias Thoms, Ed Hurt, Irmgard Sinning, Gert Bange, and Dieter Kressler. Co-translational capturing of nascent ribosomal proteins by their dedicated chaperones. Nature Communications, Jun 2015. URL: https://doi.org/10.1038/ncomms8494, doi:10.1038/ncomms8494. This article has 93 citations and is from a highest quality peer-reviewed journal.
(mitterer2016nuclearimportof pages 1-2): Valentin Mitterer, Nadine Gantenbein, Ruth Birner-Gruenberger, Guillaume Murat, Helmut Bergler, Dieter Kressler, and Brigitte Pertschy. Nuclear import of dimerized ribosomal protein rps3 in complex with its chaperone yar1. Scientific Reports, Nov 2016. URL: https://doi.org/10.1038/srep36714, doi:10.1038/srep36714. This article has 38 citations and is from a peer-reviewed journal.
(mitterer2016nuclearimportof pages 2-4): Valentin Mitterer, Nadine Gantenbein, Ruth Birner-Gruenberger, Guillaume Murat, Helmut Bergler, Dieter Kressler, and Brigitte Pertschy. Nuclear import of dimerized ribosomal protein rps3 in complex with its chaperone yar1. Scientific Reports, Nov 2016. URL: https://doi.org/10.1038/srep36714, doi:10.1038/srep36714. This article has 38 citations and is from a peer-reviewed journal.
(mitterer2016nuclearimportof media 8e76864a): Valentin Mitterer, Nadine Gantenbein, Ruth Birner-Gruenberger, Guillaume Murat, Helmut Bergler, Dieter Kressler, and Brigitte Pertschy. Nuclear import of dimerized ribosomal protein rps3 in complex with its chaperone yar1. Scientific Reports, Nov 2016. URL: https://doi.org/10.1038/srep36714, doi:10.1038/srep36714. This article has 38 citations and is from a peer-reviewed journal.
(mitterer2016nuclearimportof media 4e812712): Valentin Mitterer, Nadine Gantenbein, Ruth Birner-Gruenberger, Guillaume Murat, Helmut Bergler, Dieter Kressler, and Brigitte Pertschy. Nuclear import of dimerized ribosomal protein rps3 in complex with its chaperone yar1. Scientific Reports, Nov 2016. URL: https://doi.org/10.1038/srep36714, doi:10.1038/srep36714. This article has 38 citations and is from a peer-reviewed journal.
(koch2012yar1protectsthe pages 4-6): Barbara Koch, Valentin Mitterer, Johannes Niederhauser, Tamsyn Stanborough, Guillaume Murat, Gerald Rechberger, Helmut Bergler, Dieter Kressler, and Brigitte Pertschy. Yar1 protects the ribosomal protein rps3 from aggregation. Journal of Biological Chemistry, 287:21806-21815, Jun 2012. URL: https://doi.org/10.1074/jbc.m112.365791, doi:10.1074/jbc.m112.365791. This article has 78 citations and is from a domain leading peer-reviewed journal.
(koch2012yar1protectsthe pages 6-7): Barbara Koch, Valentin Mitterer, Johannes Niederhauser, Tamsyn Stanborough, Guillaume Murat, Gerald Rechberger, Helmut Bergler, Dieter Kressler, and Brigitte Pertschy. Yar1 protects the ribosomal protein rps3 from aggregation. Journal of Biological Chemistry, 287:21806-21815, Jun 2012. URL: https://doi.org/10.1074/jbc.m112.365791, doi:10.1074/jbc.m112.365791. This article has 78 citations and is from a domain leading peer-reviewed journal.
(loar2004geneticandbiochemical pages 9-11): Jesse W Loar, Robert M Seiser, Alexandra E Sundberg, Holly J Sagerson, Nasreen Ilias, Pamela Zobel-Thropp, Elizabeth A Craig, and Deborah E Lycan. Genetic and biochemical interactions among yar1, ltv1 and rps3 define novel links between environmental stress and ribosome biogenesis in saccharomyces cerevisiae. Genetics, 168:1877-1889, Dec 2004. URL: https://doi.org/10.1534/genetics.104.032656, doi:10.1534/genetics.104.032656. This article has 70 citations and is from a domain leading peer-reviewed journal.
(loar2004geneticandbiochemical pages 8-9): Jesse W Loar, Robert M Seiser, Alexandra E Sundberg, Holly J Sagerson, Nasreen Ilias, Pamela Zobel-Thropp, Elizabeth A Craig, and Deborah E Lycan. Genetic and biochemical interactions among yar1, ltv1 and rps3 define novel links between environmental stress and ribosome biogenesis in saccharomyces cerevisiae. Genetics, 168:1877-1889, Dec 2004. URL: https://doi.org/10.1534/genetics.104.032656, doi:10.1534/genetics.104.032656. This article has 70 citations and is from a domain leading peer-reviewed journal.
(yang2023chaperonedirectedribosomerepair pages 5-7): Yoon-Mo Yang, Youngeun Jung, Daniel Abegg, Alexander Adibekian, Kate S. Carroll, and Katrin Karbstein. Chaperone-directed ribosome repair after oxidative damage. Molecular Cell, 83:1527-1537.e5, May 2023. URL: https://doi.org/10.1016/j.molcel.2023.03.030, doi:10.1016/j.molcel.2023.03.030. This article has 70 citations and is from a highest quality peer-reviewed journal.
(yang2024ribosomeassemblyand pages 8-9): Yoon-Mo Yang and Katrin Karbstein. Ribosome assembly and repair. Annual Review of Cell and Developmental Biology, 40:241-264, Oct 2024. URL: https://doi.org/10.1146/annurev-cellbio-111822-113326, doi:10.1146/annurev-cellbio-111822-113326. This article has 18 citations and is from a domain leading peer-reviewed journal.
(martinvillanueva2024thebeakof pages 10-11): Sara Martín-Villanueva, Carla V. Galmozzi, Carmen Ruger-Herreros, Dieter Kressler, and Jesús de la Cruz. The beak of eukaryotic ribosomes: life, work and miracles. Biomolecules, 14:882, Jul 2024. URL: https://doi.org/10.3390/biom14070882, doi:10.3390/biom14070882. This article has 4 citations.
(mitterer2016nuclearimportof pages 4-5): Valentin Mitterer, Nadine Gantenbein, Ruth Birner-Gruenberger, Guillaume Murat, Helmut Bergler, Dieter Kressler, and Brigitte Pertschy. Nuclear import of dimerized ribosomal protein rps3 in complex with its chaperone yar1. Scientific Reports, Nov 2016. URL: https://doi.org/10.1038/srep36714, doi:10.1038/srep36714. This article has 38 citations and is from a peer-reviewed journal.
id: P46683
gene_symbol: YAR1
product_type: PROTEIN
status: COMPLETE
taxon:
id: NCBITaxon:559292
label: Saccharomyces cerevisiae
description: >-
YAR1 encodes an ankyrin repeat protein that functions as a dedicated chaperone
for the small ribosomal subunit protein Rps3. Yar1 binds newly synthesized Rps3,
prevents Rps3 aggregation, supports its solubility and nuclear delivery, and
thereby promotes small ribosomal subunit biogenesis and export. The conserved
ankyrin-repeat/PANTHER family context explains domain architecture but does
not support transferred MBF/SBF transcription-complex annotations for yeast
Yar1.
existing_annotations:
- term:
id: GO:0001228
label: DNA-binding transcription activator activity, RNA polymerase II-specific
evidence_type: IBA
original_reference_id: GO_REF:0000033
review:
summary: The IBA transcription-activator annotation is not supported for yeast Yar1.
action: REMOVE
reason: The direct literature establishes Yar1 as an Rps3-specific ribosomal-protein chaperone, not as a DNA-binding transcription activator; this appears to be an inappropriate family transfer.
supported_by:
- reference_id: PMID:22570489
supporting_text: Yar1 directly interacts with the small ribosomal subunit protein Rps3 and accompanies newly synthesized Rps3 from the cytoplasm into the nucleus.
- term:
id: GO:0045944
label: positive regulation of transcription by RNA polymerase II
evidence_type: IBA
original_reference_id: GO_REF:0000033
review:
summary: Positive regulation of RNA polymerase II transcription is not supported as a direct Yar1 function.
action: REMOVE
reason: Yar1's experimentally supported role is Rps3 chaperoning and 40S biogenesis; the transcription regulation annotation is inconsistent with the yeast evidence.
- term:
id: GO:0030907
label: MBF transcription complex
evidence_type: IBA
original_reference_id: GO_REF:0000033
review:
summary: MBF transcription complex membership is not supported for yeast Yar1.
action: REMOVE
reason: The PANTHER ankyrin-repeat family is broad and does not justify transferring MBF complex membership to Yar1; yeast evidence supports Rps3 binding instead.
supported_by:
- reference_id: file:interpro/panther/PTHR24198/PTHR24198-metadata.yaml
supporting_text: PTHR24198 is a broad ankyrin repeat domain-containing protein family rather than a Yar1-specific transcription complex family.
- term:
id: GO:0033309
label: SBF transcription complex
evidence_type: IBA
original_reference_id: GO_REF:0000033
review:
summary: SBF transcription complex membership is not supported for yeast Yar1.
action: REMOVE
reason: The experimentally supported Yar1 function is as a dedicated Rps3 chaperone in ribosome biogenesis, not as an SBF subunit.
- term:
id: GO:0005515
label: protein binding
evidence_type: IPI
original_reference_id: PMID:15611164
review:
summary: Generic protein binding is uninformative for Yar1.
action: MARK_AS_OVER_ANNOTATED
reason: PMID:15611164 supports a specific Yar1-Rps3/Ltv1 ribosome-biogenesis context; the generic protein binding term should not replace the more informative chaperone and ribosome-biogenesis annotations.
- term:
id: GO:0005515
label: protein binding
evidence_type: IPI
original_reference_id: PMID:37968396
review:
summary: Interactome-derived protein binding is too generic to retain as core.
action: MARK_AS_OVER_ANNOTATED
reason: The core molecular role is Rps3-specific chaperoning, not undifferentiated protein binding from a broad interactome.
- term:
id: GO:0051082
label: unfolded protein binding
evidence_type: IDA
original_reference_id: PMID:26112308
review:
summary: Yar1 acts as a dedicated protein-carrier chaperone for Rps3, so the broader term should be replaced.
action: MODIFY
reason: Yar1 protects Rps3 from aggregation and keeps it soluble before pre-ribosome incorporation; GO:0140597 captures this carrier-chaperone role better than generic unfolded-protein binding.
proposed_replacement_terms:
- id: GO:0140597
label: protein carrier chaperone
supported_by:
- reference_id: PMID:22570489
supporting_text: Yar1 protects Rps3 from aggregation in vitro and increases its solubility in vivo.
- reference_id: file:yeast/YAR1/YAR1-deep-research-falcon.md
supporting_text: Falcon synthesis supports Yar1 as a dedicated Rps3 carrier chaperone rather than a general unfolded-protein binding factor.
- term:
id: GO:0005737
label: cytoplasm
evidence_type: HDA
original_reference_id: PMID:14562095
review:
summary: Cytoplasmic localization is consistent with Yar1's interaction with newly synthesized Rps3.
action: ACCEPT
reason: Yar1 binds nascent Rps3 in the cytoplasm before accompanying it to the nuclear pre-ribosome assembly site.
- term:
id: GO:0000056
label: ribosomal small subunit export from nucleus
evidence_type: IMP
original_reference_id: PMID:22570489
review:
summary: Yar1 supports small-subunit export indirectly through Rps3 maturation and pre-40S biogenesis.
action: ACCEPT
reason: yar1 deletion phenocopies ltv1 deletion with a small-subunit export defect; because Yar1 acts upstream by stabilizing Rps3, the BP annotation is retained.
supported_by:
- reference_id: PMID:22570489
supporting_text: A yar1 deletion strain displays a similar phenotype as an rps3 mutant strain, showing an accumulation of 20S pre-rRNA and a 40S export defect.
- term:
id: GO:0000056
label: ribosomal small subunit export from nucleus
evidence_type: IGI
original_reference_id: PMID:22570489
review:
summary: Genetic interaction evidence supports a Yar1 contribution to 40S export.
action: ACCEPT
reason: The export phenotype follows from defective Rps3 handling and 40S maturation, so this is valid but downstream of Yar1's chaperone activity.
- term:
id: GO:0005634
label: nucleus
evidence_type: IDA
original_reference_id: PMID:22570489
review:
summary: Yar1 accompanies Rps3 into the nucleus during pre-ribosome assembly.
action: ACCEPT
reason: Direct microscopy/biochemical evidence shows Yar1 travels with newly synthesized Rps3 from cytoplasm into the nucleus.
supported_by:
- reference_id: PMID:22570489
supporting_text: Yar1 directly interacts with the small ribosomal subunit protein Rps3 and accompanies newly synthesized Rps3 from the cytoplasm into the nucleus.
- term:
id: GO:0005634
label: nucleus
evidence_type: IGI
original_reference_id: PMID:22570489
review:
summary: Nuclear localization is consistent with Yar1's Rps3 delivery route.
action: ACCEPT
reason: Yar1 escorts Rps3 to the nuclear pre-ribosome assembly compartment.
- term:
id: GO:0006970
label: response to osmotic stress
evidence_type: IMP
original_reference_id: PMID:15611164
review:
summary: Osmotic-stress phenotypes are secondary to Yar1's ribosome-biogenesis role.
action: KEEP_AS_NON_CORE
reason: PMID:15611164 links yar1 deletion to environmental stress sensitivity, but the mechanistic basis is ribosome biogenesis and Rps3 handling rather than a dedicated stress-response function.
- term:
id: GO:0032880
label: regulation of protein localization
evidence_type: IMP
original_reference_id: PMID:22570489
review:
summary: Yar1 regulates Rps3 localization by keeping Rps3 soluble and escorting it to the nucleus.
action: ACCEPT
reason: The term captures Yar1's direct effect on Rps3 localization before pre-40S assembly.
supported_by:
- reference_id: PMID:22570489
supporting_text: Yar1 directly interacts with the small ribosomal subunit protein Rps3 and accompanies newly synthesized Rps3 from the cytoplasm into the nucleus.
- term:
id: GO:0032880
label: regulation of protein localization
evidence_type: IPI
original_reference_id: PMID:22570489
review:
summary: Protein-localization regulation is supported by Yar1-Rps3 interaction evidence.
action: ACCEPT
reason: Yar1 binding promotes productive Rps3 delivery and suppresses defects caused by yar1 deletion.
- term:
id: GO:0034599
label: cellular response to oxidative stress
evidence_type: IMP
original_reference_id: PMID:15611164
review:
summary: Oxidative-stress phenotypes are retained as non-core.
action: KEEP_AS_NON_CORE
reason: Stress sensitivity is experimentally observed in yar1 mutants, but available evidence points to ribosome biogenesis defects as the core molecular basis.
- term:
id: GO:0042274
label: ribosomal small subunit biogenesis
evidence_type: IMP
original_reference_id: PMID:15611164
review:
summary: Ribosomal small subunit biogenesis is a core Yar1 biological role.
action: ACCEPT
reason: Yar1 acts through Rps3, a 40S subunit protein; yar1 deletion causes ribosome-biogenesis defects that are suppressed by RPS3 overexpression.
supported_by:
- reference_id: PMID:15611164
supporting_text: Overexpression of RPS3 suppresses both the stress sensitivity and the ribosome biogenesis defect of Deltayar1.
- term:
id: GO:0042274
label: ribosomal small subunit biogenesis
evidence_type: IGI
original_reference_id: PMID:15611164
review:
summary: Genetic interaction evidence supports Yar1 function in 40S biogenesis.
action: ACCEPT
reason: Yar1, Ltv1, and Rps3 interactions define a pathway connecting Rps3 handling to small ribosomal subunit production.
- term:
id: GO:0051082
label: unfolded protein binding
evidence_type: IMP
original_reference_id: PMID:22570489
review:
summary: Yar1's substrate binding is a specific carrier-chaperone function for Rps3.
action: MODIFY
reason: The replacement term GO:0140597 reflects Yar1's dedicated role in binding and carrying nascent Rps3 to prevent aggregation.
proposed_replacement_terms:
- id: GO:0140597
label: protein carrier chaperone
supported_by:
- reference_id: PMID:26112308
supporting_text: Affinity purification of four chaperones (Rrb1, Syo1, Sqt1 and Yar1) selectively enriched the mRNAs encoding their specific ribosomal protein clients.
core_functions:
- molecular_function:
id: GO:0140597
label: protein carrier chaperone
directly_involved_in:
- id: GO:0042274
label: ribosomal small subunit biogenesis
- id: GO:0032880
label: regulation of protein localization
locations:
- id: GO:0005737
label: cytoplasm
- id: GO:0005634
label: nucleus
description: >-
Yar1 is a dedicated carrier chaperone for Rps3. It binds nascent Rps3,
maintains Rps3 solubility, and accompanies Rps3 from cytoplasm to nucleus so
it can be incorporated into pre-40S ribosomal particles.
supported_by:
- reference_id: PMID:22570489
supporting_text: Yar1 protects Rps3 from aggregation in vitro and increases its solubility in vivo.
- reference_id: PMID:26112308
supporting_text: Affinity purification of four chaperones (Rrb1, Syo1, Sqt1 and Yar1) selectively enriched the mRNAs encoding their specific ribosomal protein clients.
- reference_id: file:yeast/YAR1/YAR1-deep-research-falcon.md
supporting_text: Falcon literature synthesis supports Yar1 as an Rps3-specific ribosomal protein carrier chaperone.
proposed_new_terms: []
suggested_questions:
- question: >-
Should yeast Yar1 annotations explicitly distinguish Rps3 carrier-chaperone
activity from downstream 40S export phenotypes?
suggested_experiments:
- description: >-
Test whether point mutations that disrupt the Yar1-Rps3 interface abolish
Rps3 solubility and nuclear delivery without broadly altering stress-response
pathways.
references:
- id: GO_REF:0000033
title: Annotation inferences using phylogenetic trees
findings: []
- id: PMID:14562095
title: Global analysis of protein localization in budding yeast.
findings: []
- id: PMID:15611164
title: Genetic and biochemical interactions among Yar1, Ltv1 and Rps3 define novel links between environmental stress and ribosome biogenesis in Saccharomyces cerevisiae.
findings: []
- id: PMID:22570489
title: Yar1 protects the ribosomal protein Rps3 from aggregation.
findings: []
- id: PMID:26112308
title: Co-translational capturing of nascent ribosomal proteins by their dedicated chaperones.
findings: []
- id: PMID:37968396
title: The social and structural architecture of the yeast protein interactome.
findings: []
- id: file:yeast/YAR1/YAR1-deep-research-falcon.md
title: Falcon deep research synthesis for YAR1
findings: []
- id: file:interpro/panther/PTHR24198/PTHR24198-metadata.yaml
title: PANTHER family PTHR24198 ankyrin repeat metadata
findings: []