RIM15

Summary: RIM15 is a serine/threonine protein kinase with extensive experimental validation of catalytic activity across multiple direct substrates (Igo1/2, Rph1, Hsf1, Msn2). IBA annotation based on phylogenetic inference is appropriate.

Reason: Direct biochemical evidence confirms RIM15 phosphorylates Ser and Thr residues in multiple substrates. Catalytic activity is central to RIM15 mechanism of action.

Summary: RIM15 integrates signals from three major nutrient-sensing kinases (TOR, PKA, Sch9) to transduce nutrient limitation signals. This is a core function central to RIM15 activation of quiescence programs.

Reason: RIM15 serves as a nutrient signal integrator that receives inhibitory inputs from TOR/PKA/Sch9 and converts these into activation of G0 entry program. This is signal transduction in the strict sense - integrating multiple input signals to produce a cellular response.

Summary: RIM15 is involved in regulation of cell cycle progression through G1/G0 transition, but phylogenetically inferred annotation may be too broad or incorrectly ancestral inferred.

Reason: RIM15's role is specifically in G1 to G0 transition (quiescence entry), not general mitotic cell cycle regulation. GO:1903452 (positive regulation of G1 to G0 transition) is more specific and mechanistically accurate. The IBA annotation appears to be an over-generalization.

Proposed replacements: positive regulation of G1 to G0 transition

Summary: RIM15 localizes to both nucleus and cytoplasm. Nuclear localization is directly demonstrated experimentally.

Reason: RIM15 localizes to nucleus in response to nutrient starvation signals, which is essential for its function in activating stress response transcription factors.

Summary: RIM15 localizes to cytoplasm in growing cells. Cytoplasmic sequestration is a regulatory mechanism for inactivating RIM15.

Reason: RIM15 is exported to cytoplasm under favorable growth conditions (when TOR/PKA are active), which inactivates it. This is experimentally demonstrated.

Summary: RIM15 has a response regulatory domain (InterPro:IPR001789) detected via InterPro. However, RIM15 is not known to function as part of a classic two-component phosphorelay system in yeast.

Reason: While RIM15 does contain a response regulatory domain by sequence homology, it does not participate in phosphorelay signal transduction in yeast. RIM15 is activated by inactivation of upstream kinases (TOR, PKA), not by phosphorylation as in typical phosphorelay systems. This is a false positive from InterPro domain annotation.

Summary: RIM15 binds ATP as a serine/threonine kinase. This is a generic molecular function present in all kinases.

Reason: While technically correct (ATP binding is required for kinase catalysis), this term is generic and uninformative for describing RIM15 function. More specific kinase activity terms (GO:0004674) are preferred.

Summary: RIM15 is a protein kinase - this is a generic parent term to GO:0004674 (serine/threonine kinase activity).

Reason: RIM15 is correctly inferred as a protein kinase via InterPro domain annotation. While GO:0004674 is more specific, this parent term is still valid and commonly annotated.

Summary: RIM15 catalyzes phosphorylation of serine and threonine residues. Inference via InterPro and EC number is appropriate for kinase subfamily.

Reason: RIM15 is confirmed to phosphorylate serine and threonine residues in multiple substrates. IEA inference via InterPro and EC:2.7.11.1 is reliable for this well-characterized kinase subfamily.

Summary: ATP binding is a generic molecular function of all kinases.

Reason: While correct, this term provides minimal functional information. Specific kinase activity terms are more informative.

Summary: RIM15 localizes to nucleus based on UniProtKB subcellular location vocabulary mapping.

Reason: Nuclear localization is directly demonstrated by multiple studies and is essential for RIM15's function in activating transcription factors.

Summary: RIM15 localizes to cytoplasm based on UniProtKB subcellular location vocabulary.

Reason: Dual localization to both nucleus and cytoplasm is mechanistically important for RIM15 regulation - cytoplasmic sequestration inactivates the kinase.

Summary: RIM15 is activated by various stress conditions and orchestrates stress response programs.

Reason: RIM15 responds to nutrient limitation, oxidative stress, and heat stress to activate appropriate stress response genes through phosphorylation of transcription factors.

Summary: Generic parent term for kinase activity.

Reason: Correct but less specific than serine/threonine kinase activity (GO:0004674).

Summary: Generic parent term for all transferase activities, including kinases.

Reason: Correct but extremely generic. Specific kinase terms are more informative.

Summary: RIM15 is involved in meiosis, stimulating expression of early meiotic genes on glucose depletion. This IEA is inferred from the UniProtKB keyword "Meiosis" and is corroborated by the independent SGD IMP for the same term on PMID:9111339.

Reason: The meiotic involvement is real but is one of several downstream outputs of RIM15's core nutrient-signalling kinase activity (quiescence entry, stress-response gene induction, autophagy, chronological lifespan), so it is retained as non-core rather than as a core function. No replacement term is proposed, because GO has deliberately obsoleted the meiosis-scoped transcription-regulation terms (GO:0051039 and GO:0010673) as GO-CAM-shaped, and both carry "consider" pointers to GO:0045944 and GO:0051321 used together rather than merged. The transcriptional mechanism is therefore already captured additively by the separate GO:0045944 IMP annotation on this same paper, and swapping this term for GO:0045944 would discard the meiotic context rather than refine it.

Summary: RIM15 phosphorylates serine residues. Inference via Rhea mapping to EC:2.7.11.1 is appropriate.

Reason: RIM15 phosphorylates both serine and threonine residues, so serine kinase activity is a subset of its activity but correctly inferred from EC number.

Summary: Inferred from ARBA machine learning model. RIM15 regulates G1/G0 transition, not general mitotic phase transitions.

Reason: This term is misleading. RIM15 promotes G1 to G0 transition (growth arrest), not mitotic phase progression. GO:1903452 is more accurate.

Proposed replacements: positive regulation of G1 to G0 transition

Summary: RIM15 interacts with proteins in large-scale mass spectrometry complex identification study.

Reason: Protein binding is too generic to be informative. GO:0005515 should only be used when the specific binding partner and biological consequence are documented. Without identifying which proteins RIM15 binds, this annotation conveys no functional information.

Summary: RIM15 identified in chaperone interaction study.

Reason: Protein binding is too generic. While RIM15 may interact with chaperones, this conveys minimal functional information without specificity.

Summary: RIM15 interacts with kinase/phosphatase network partners (e.g., KIN2/PHO85).

Reason: Generic protein binding term without specificity. RIM15's interactions with Pho85 and other kinases/phosphatases are better captured by more specific functional annotations (substrate phosphorylation, signal transduction).

Summary: Recent study demonstrates RIM15's role in cellular antioxidant systems and oxidative stress tolerance through transcriptional regulation.

Reason: Direct experimental evidence shows RIM15 mediates response to hydrogen peroxide and oxidative stress through activation of antioxidant genes.

Summary: RIM15 is required for proper cellular response to hydrogen peroxide specifically.

Reason: Direct experimental evidence shows RIM15 mediates response to H2O2 as part of oxidative stress response pathway.

Summary: RIM15 is involved in heat stress response through regulation of Hsf1 transcription factor.

Reason: RIM15 phosphorylates and activates Hsf1, which is the heat shock transcription factor. This directly links RIM15 to heat stress response.

Summary: RIM15 stimulates transcription of meiotic genes through activation of Ime1p and interaction with Ume6p transcriptional complex.

Reason: RIM15 promotes meiotic gene expression through phosphorylation and transcriptional activation pathways.

Summary: RIM15 was originally identified through a mutation causing reduced ability to undergo meiosis, and its deletion reduces expression of the early meiotic genes IME2, SPO13 and HOP1 as well as of IME1.

Reason: The mutant phenotype reported in this paper is direct IMP support for meiotic involvement, so the SGD curator's term stands (full text is not available to us, per CLAUDE.md we do not overrule an experimental annotation we cannot fully inspect). It is marked non-core because RIM15's core function is nutrient-responsive serine/threonine kinase activity, of which meiotic entry is one downstream output alongside quiescence, stress response and autophagy. The transcriptional mechanism is expressed additively rather than as a swap, via the separate GO:0045944 IMP annotation on this same reference; this matches GO's own guidance, since the merged terms (GO:0051039, GO:0010673) are obsolete and direct users to GO:0045944 and GO:0051321 together.

Summary: Direct evidence of RIM15 protein kinase activity demonstrated through in vitro phosphorylation assays on Hsf1 and Msn2.

Reason: Direct kinase activity assays demonstrate RIM15 can phosphorylate multiple substrates. IDA evidence is strong for kinase activity.

Summary: RIM15 shows autophosphorylation activity and can phosphorylate downstream substrates.

Reason: Direct biochemical evidence of protein kinase activity - autophosphorylation and substrate phosphorylation demonstrated.

Summary: Direct biochemical evidence shows RIM15 has protein kinase activity and that PKA-mediated phosphorylation inhibits this activity.

Reason: In vitro kinase assays confirm RIM15 phosphorylates substrates. Activity regulation by PKA demonstrates kinase activity is functionally important.

Summary: RIM15 phosphorylates Igo1 and Igo2 endosulfines at serine/threonine residues.

Reason: Direct evidence of serine/threonine kinase activity on known substrates Igo1/Igo2.

Summary: RIM15's serine/threonine kinase activity is functionally required for G0 program initiation through phosphorylation of downstream substrates.

Reason: Functional evidence shows RIM15 kinase activity is essential for its biological role in quiescence entry. IMP evidence complements IDA biochemical evidence.

Summary: Direct evidence shows RIM15 phosphorylates endosulfines Igo1/Igo2.

Reason: Direct biochemical evidence of serine/threonine kinase activity on characterized substrates. Multiple independent lines of IDA evidence support this annotation.

Summary: RIM15 is phosphorylated at multiple serine/threonine residues in global phosphorylation study.

Reason: HDA annotation is supported by multiple direct kinase activity assays (IDA evidence) from independent studies, confirming RIM15 is a protein kinase.

Summary: Global protein localization study identifies RIM15 in cytoplasm.

Reason: HDA evidence for localization is supported by more direct IDA evidence (PMID:14690612) that demonstrates both nuclear and cytoplasmic localization. HDA is consistent with direct evidence.

Summary: Functional evidence shows RIM15 regulates mitotic cell cycle phase transitions, specifically G1/G0 transition.

Reason: RIM15's specific role is in G1 to G0 transition (quiescence, non-mitotic growth arrest), not mitotic cell cycle phase transitions. GO:1903452 is more mechanistically accurate.

Proposed replacements: positive regulation of G1 to G0 transition

Summary: RIM15 is required for initiation of G0 program following nutrient limitation through direct phosphorylation of Igo1/2.

Reason: This is a core function of RIM15. Direct molecular evidence shows RIM15 phosphorylates Igo1/2, which are essential for G0 program initiation.

Summary: RIM15 and endosulfines (Igo1/2) function together to promote G0 entry and extend chronological lifespan.

Reason: Genetic interaction evidence shows RIM15 and Igo1/2 cooperate to regulate quiescence entry. This supports the functional annotation.

Summary: RIM15 is required for proper G1 arrest in stationary phase. Deletion of RIM15 causes defects in G1 arrest.

Reason: RIM15 is essential for entry into stationary phase (G0) and proper G1 growth arrest. This is a well-established primary function.

Summary: RIM15 is required for proper transcriptional response to nitrogen limitation through phosphorylation of Rph1.

Reason: RIM15 mediates nutrient-limitation signaling in response to nitrogen starvation through Rph1 phosphorylation and autophagy induction.

Summary: RIM15 and Rph1 function together to mediate response to nitrogen starvation and autophagy induction.

Reason: Genetic interaction data show RIM15 and Rph1 cooperate in nitrogen starvation response. RIM15 phosphorylates Rph1 to relieve its repression of autophagy genes.

Summary: RIM15 promotes autophagy induction during nutrient starvation by phosphorylating Rph1, which relieves transcriptional repression of ATG genes.

Reason: RIM15 phosphorylates Rph1 to inactivate its repressive function, allowing induction of autophagy genes. This is a direct mechanistic role in autophagy regulation.

Summary: RIM15 and Rph1 have antagonistic genetic interaction in autophagy regulation.

Reason: Genetic interaction evidence further supports RIM15's role in autophagy induction as a downstream effector of nutrient sensing.

Summary: RIM15 localizes to the nucleus, particularly under nutrient limitation. Nuclear localization is essential for activating transcription factors.

Reason: Direct experimental evidence demonstrates RIM15 nuclear accumulation as a key regulatory mechanism. This is a core aspect of RIM15 mechanism.

Summary: RIM15 localizes to cytoplasm under nutrient-rich conditions where it is inactive.

Reason: Dual localization mechanism - cytoplasmic sequestration under nutrient-rich conditions, nuclear accumulation under starvation - is essential for RIM15 regulation.