Summary: Telomeric-region localization inferred automatically (inter-ontology link) from the GO:0031509 subtelomeric heterochromatin formation IMP, which is itself misattributed.

Reason: This IEA (GO_REF:0000108) has GO:0031509 in its with/from column, so its only basis is the SGD IMP for subtelomeric heterochromatin formation from PMID:11731479, which is removed below because that paper reports no SAS3 mutant phenotype. No other source checked here (PMID:8782818, PMID:16581777) places SAS3 or NuA3 at telomeres or reports a SAS3 telomeric phenotype, so nothing else supports this location. SAS3/NuA3 acts mainly on euchromatic coding regions.

Summary: chromatin is consistent with curated evidence for SAS3 function in NuA3-associated chromatin acetylation.

Reason: Accepted as concordant with SAS3 molecular role and literature-supported complex/process context.

Summary: chromatin binding is consistent with curated evidence for SAS3 function in NuA3-associated chromatin acetylation.

Reason: Accepted as concordant with SAS3 molecular role and literature-supported complex/process context.

Summary: transcription coregulator activity is consistent with curated evidence for SAS3 function in NuA3-associated chromatin acetylation.

Reason: Accepted as concordant with SAS3 molecular role and literature-supported complex/process context. Falcon deep research documents physical/functional coupling of Sas3/NuA3 to the FACT elongation factor (Spt16), consistent with a transcription coregulator role.

Summary: histone acetyltransferase activity is consistent with curated evidence for SAS3 function in NuA3-associated chromatin acetylation.

Reason: Accepted as concordant with SAS3 molecular role and literature-supported complex/process context. Falcon deep research confirms Sas3 is the MYST-family catalytic HAT subunit of NuA3 that acetylates histone H3 (primarily H3K14).

Summary: Generic protein binding is not sufficiently informative for SAS3 curation.

Reason: Removed because SAS3 interaction biology is better captured by specific NuA3 complex and histone-acetyltransferase annotations than by broad GO:0005515.

Summary: nucleus is consistent with curated evidence for SAS3 function in NuA3-associated chromatin acetylation.

Reason: Accepted as concordant with SAS3 molecular role and literature-supported complex/process context. Falcon deep research places Sas3/NuA3 in the nucleus on chromatin, associating with transcribed gene bodies.

Summary: regulation of DNA-templated transcription is consistent with curated evidence for SAS3 function in NuA3-associated chromatin acetylation.

Reason: Accepted as concordant with SAS3 molecular role and literature-supported complex/process context. Falcon deep research supports a chromatin-context-sensitive transcriptional-regulatory role, with NuA3 reader modules targeting acetylation to active chromatin marks.

Summary: regulation of transcription by RNA polymerase II is consistent with curated evidence for SAS3 function in NuA3-associated chromatin acetylation.

Reason: Accepted as concordant with SAS3 molecular role and literature-supported complex/process context. Falcon deep research supports a transcriptional-regulatory role, including antagonism of Rpd3S/Rpd3L HDACs to tune mRNA/lncRNA expression dynamics.

Summary: This silencing annotation rests on a misattributed reference. PMID:11731479 (Osada et al. 2001) is about the SAS-I silencing complex (Sas2p, Sas4p, Sas5p) and Sas2p-mediated silencing at HML and telomeres; SAS3 (Ybf2/Sas3) appears only in the MYST-family acronym, as background, and as the sequence template for the SAS2 acetyl-CoA-motif mutants. The paper provides no SAS3-specific silencing evidence. The process term itself is defensible for SAS3 on other evidence (PMID:8782818), so the row is kept and demoted rather than removed; the reference problem goes to SGD.

Reason: Kept as non-core rather than removed, because the term is defensible for SAS3 but the cited reference is wrong (same handling as the misattributed IDA in genes/human/AHI1). The IMP annotation is misattributed. PMID:11731479 characterizes the SAS-I silencing complex (Sas2/Sas4/Sas5) and demonstrates that Sas2p (not Sas3p) mediates silencing at HML and telomeres; SAS3 appears only in the MYST acronym. SAS3 was independently identified in a screen for enhancers of sir1 silencing defects (PMID:8782818, Reifsnyder et al. 1996), and UniProt attributes HMR silencing involvement to that paper and to PMID:16581777, so the proposed upstream fix is to re-reference the annotation to PMID:8782818 rather than retract it (see suggested_questions). PMID:16581777 (Martin et al. 2006) is not a re-reference target for this positive process term. Its full text (PMC1446952; the local cache is abstract-only) shows the opposite direction at HMR, where deletion of NuA3 components, including sas3, rescues the silencing defect of HMR-E silencer mutants (Fig. 4B), which the authors attribute to reduced acetylation spreading into the silent locus. The SAS3 silencing evidence is therefore mixed, and non-core is the right status, since the characterised SAS3 activity is euchromatic H3K14 acetylation. Verified against the full text (PMC312835; the local cache is abstract-only) - the yeast strain table (Table 1) contains sas2, sas4, sas5, sir1 and asf1 alleles but no sas3 allele, and Sas3p is mentioned only as background and as the template for the SAS2 M1-M3 acetyl-CoA-motif point mutants. No SAS3 mutant phenotype is reported, so this is not an abstract-only judgment; the reference most likely belongs to the SAS2/SAS4/SAS5 annotations and should be reported to SGD.

Summary: This general process term is entailed by the more specific GO:0030466 (silent mating-type cassette heterochromatin formation), which this review keeps as non-core.

Reason: GO:0030466 is a descendant of this term and is kept as non-core on the basis of the sir1-enhancer screen (PMID:8782818), so by the true-path rule this parent is also true for SAS3. It carries the same non-core status and adds no information beyond the retained child. The SAS3 silencing evidence is mixed (PMID:16581777 shows sas3 deletion rescuing HMR-E silencer mutants), and the characterised SAS3 activity is euchromatic H3K14 acetylation, so heterochromatin formation is not a core function.

Summary: This silencing annotation rests on a misattributed reference. PMID:11731479 (Osada et al. 2001) shows that Sas2p, via the SAS-I complex (Sas2p, Sas4p, Sas5p), promotes silencing at telomeres; the conserved acetyl-CoA binding motif mutated to demonstrate this is in Sas2p, not Sas3p. SAS3 (Ybf2/Sas3) appears only in the MYST-family acronym, as background, and as the sequence template for the SAS2 acetyl-CoA-motif mutants. The paper provides no SAS3-specific telomeric/subtelomeric silencing evidence.

Reason: Removed because the IMP annotation is misattributed. PMID:11731479 demonstrates telomeric silencing is mediated by Sas2p (acetyl-CoA-motif mutations in Sas2p, the SAS-I complex), not by Sas3p; SAS3 appears only in the MYST acronym. SAS3/NuA3 acts mainly as a euchromatic H3K14 acetyltransferase in the 5' half of coding regions. The sources checked here give no SAS3 telomeric-silencing phenotype to re-reference this row to. The abstract of PMID:8782818 reports SAS3 as an enhancer of sir1 silencing defects, a mating-type rather than telomeric assay, and the full text of PMID:16581777 (PMC1446952), the other UniProt source for SAS3 silencing, reports only an HMR phenotype (sas3 deletion rescuing HMR-E silencer mutants) and mentions telomeric silencing only for SET1. Verified against the full text (PMC312835; the local cache is abstract-only) - the yeast strain table (Table 1) contains sas2, sas4, sas5, sir1 and asf1 alleles but no sas3 allele, and Sas3p is mentioned only as background and as the template for the SAS2 M1-M3 acetyl-CoA-motif point mutants. No SAS3 mutant phenotype is reported, so this is not an abstract-only judgment; the IMP most likely belongs to SAS2/SAS4/SAS5 and should be reported to SGD.

Summary: NuA3 histone acetyltransferase complex is consistent with curated evidence for SAS3 function in NuA3-associated chromatin acetylation.

Reason: Accepted as concordant with SAS3 molecular role and literature-supported complex/process context. Falcon deep research confirms Sas3 is the catalytic subunit required for both activity and integrity of the NuA3 complex.

Summary: protein-lysine-acetyltransferase activity is consistent with curated evidence for SAS3 function in NuA3-associated chromatin acetylation.

Reason: Accepted as concordant with SAS3 molecular role and literature-supported complex/process context. Falcon deep research describes the acetyl-CoA-dependent transfer of an acetyl group to the epsilon-amino group of a lysine residue, the defining reaction of lysine acetyltransferases.

Summary: H3 histone acetyltransferase complex is consistent with curated evidence for SAS3 function in NuA3-associated chromatin acetylation.

Reason: Accepted as concordant with SAS3 molecular role and literature-supported complex/process context.

Summary: NuA3a histone acetyltransferase complex is consistent with curated evidence for SAS3 function in NuA3-associated chromatin acetylation.

Reason: Accepted as concordant with SAS3 molecular role and literature-supported complex/process context.

Summary: NuA3b histone acetyltransferase complex is consistent with curated evidence for SAS3 function in NuA3-associated chromatin acetylation.

Reason: Pdp3 affinity purification, binding and genetics classify the Sas3-containing NuA3 acetyltransferase into two forms and identify NuA3b as the Pdp3-containing H3K36me3-directed complex.

Summary: histone acetyltransferase activity is consistent with curated evidence for SAS3 function in NuA3-associated chromatin acetylation.

Reason: Accepted as concordant with SAS3 molecular role and literature-supported complex/process context.

Summary: nucleus is consistent with curated evidence for SAS3 function in NuA3-associated chromatin acetylation.

Reason: Accepted as concordant with SAS3 molecular role and literature-supported complex/process context.

Summary: Generic protein binding is not sufficiently informative for SAS3 curation.

Reason: Removed because SAS3 interaction biology is better captured by specific NuA3 complex and histone-acetyltransferase annotations than by broad GO:0005515.

Summary: Generic protein binding is not sufficiently informative for SAS3 curation.

Reason: Removed because SAS3 interaction biology is better captured by specific NuA3 complex and histone-acetyltransferase annotations than by broad GO:0005515.

Summary: Generic protein binding is not sufficiently informative for SAS3 curation.

Reason: Removed because SAS3 interaction biology is better captured by specific NuA3 complex and histone-acetyltransferase annotations than by broad GO:0005515.

Summary: Generic protein binding is not sufficiently informative for SAS3 curation.

Reason: Removed because SAS3 interaction biology is better captured by specific NuA3 complex and histone-acetyltransferase annotations than by broad GO:0005515.

Summary: nucleus is consistent with curated evidence for SAS3 function in NuA3-associated chromatin acetylation.

Reason: Accepted as concordant with SAS3 molecular role and literature-supported complex/process context.

Summary: This process term is broader than the specific mechanistic role supported for SAS3.

Reason: Marked as over-annotated to favor more specific SAS3 functions (histone acetyltransferase activity, NuA3 complex membership, and transcription-regulatory process terms).

Summary: zinc ion binding is consistent with curated evidence for SAS3 function in NuA3-associated chromatin acetylation.

Reason: The Zf-MYST zinc-finger motif is required for recombinant Sas3 HAT activity, providing direct support for zinc binding as a non-core structural feature of the catalytic MYST domain.

Summary: NuA3a histone acetyltransferase complex is consistent with curated evidence for SAS3 function in NuA3-associated chromatin acetylation.

Reason: Pdp3 affinity purification, binding and genetics classify NuA3 into NuA3a and NuA3b and distinguish the Yng1 PHD/H3K4me3-recruited NuA3a form from the Pdp3-containing H3K36me3-recruited NuA3b form.

Summary: histone acetyltransferase activity is consistent with curated evidence for SAS3 function in NuA3-associated chromatin acetylation.

Reason: Accepted as concordant with SAS3 molecular role and literature-supported complex/process context.

Summary: histone acetyltransferase activity is consistent with curated evidence for SAS3 function in NuA3-associated chromatin acetylation.

Reason: Accepted as concordant with SAS3 molecular role and literature-supported complex/process context.

Summary: NuA3 histone acetyltransferase complex is consistent with curated evidence for SAS3 function in NuA3-associated chromatin acetylation.

Reason: Accepted as concordant with SAS3 molecular role and literature-supported complex/process context.

Summary: Generic Sas3-Taf14 protein binding from the NuA3 Yng1/Sas3 interaction paper.

Reason: The Yng1/Sas3 interaction study supports assembly of Sas3 with Taf14 and Yng1 inside NuA3, but a generic GO:0005515 assertion is less informative than the accepted NuA3 complex rows. The interaction evidence should be represented by complex membership rather than by bare protein binding.

Summary: Generic Sas3-Yng1 protein binding from the NuA3 Yng1/Sas3 interaction paper.

Reason: This IntAct row captures a real interaction within the NuA3 complex, but generic protein binding is not an informative Sas3 molecular function. The complex-level GO rows and the 2024 Taf14/Yng1/Sas3 assembly evidence capture the functional claim directly.

Summary: Generic Sas3-Yng1 protein binding from a genome-wide NuA3 interactome and localization study.

Reason: The 2014 interactome paper supports Yng1 as a NuA3-associated partner, but Sas3 function is better represented by NuA3a/NuA3b complex annotations and histone acetyltransferase activities than by GO:0005515 protein binding.

Summary: Recombinant Sas3 directly exhibits lysine acetyltransferase activity on histone substrates.

Reason: Takechi and Nakayama showed that recombinant Sas3 has histone acetyltransferase activity toward core histones, so the broad protein-lysine-acetyltransferase parent term is experimentally supported.

Summary: Purified NuA3 depends on Sas3 for histone acetyltransferase activity.

Reason: John et al. identified Sas3 as the catalytic subunit of NuA3 and showed that Sas3 is required for both NuA3 HAT activity and complex integrity, directly supporting the experimental protein-lysine-acetyltransferase parent row.

Summary: Sas3 directly catalyzes NuA3-dependent acetylation of histone H3 lysine 14.

Reason: This residue-specific activity is the best-supported biochemical function for Sas3/NuA3 but is absent from the current GOA rows. Direct Sas3 HAT activity, Sas3-dependence of purified NuA3 HAT activity, H3K4me3-dependent NuA3 HAT activity at H3K14, and the 2025 NuA3 structure with histone H3 tail and acetyl-CoA together support adding the existing GO molecular-function term rather than a new-term request.

Summary: Sas3 is part of the canonical NuA3 histone acetyltransferase complex associated with Yng1-mediated H3K4me3 recruitment.

Reason: The cached Taverna et al. abstract links Yng1 PHD binding to H3K4me3 with Sas3-dependent H3K14 acetylation by NuA3. Full cached NuA3 assembly evidence from PMID:38914563 enumerates the same canonical five core subunits, including Sas3, Nto1, Eaf6, Yng1 and Taf14.