SAS2

Existing Annotations Review

GO Term	Evidence	Action	Reason
GO:0046972 histone H4K16 acetyltransferase activity	IBA GO_REF:0000033	ACCEPT	Summary: SAS2 is the catalytic component of the SAS complex which acetylates H4K16 of free histones. This IBA annotation reflects phylogenetic inference and is mechanistically accurate for the specific substrate. The SAS complex specifically acetylates both H4K16 and H3K14, making this a core molecular function. Reason: UniProt explicitly states SAS2 as catalytic subunit acetylates Lys-16 of histone H4. PMID:12626510 confirms the recombinant and native SAS complex acetylates H4 lysine 16 with high specificity. IBA inference is appropriate for this well-characterized enzymatic activity. Propagation Review Root cause: NO FAILURE CORE Sources checked: PANTHER:PTN007449682 · PTN007449682 SUPPORTS TRANSFER This PAINT node transfers H4K16 acetyltransferase activity from fungal, fly, mouse, and human descendants, and S. cerevisiae Sas2 itself has direct biochemical support for the inherited H4K16 activity. Supporting Evidence: PMID:12626510 The recombinant SAS complex acetylates H4 lysine 16 and H3 lysine 14. Furthermore, a purified SAS complex from yeast shows similar activity and specificity. file:interpro/panther/PTHR10615/PTHR10615-paint.tsv PTHR10615 PTN007449682 GO:0046972 F IBD false CGD:CAL0000189453\|FB:FBgn0014340\|MGI:MGI:1915023\|UniProtKB:Q92993 taxon:33154 20241119 file:yeast/SAS2/SAS2-deep-research-falcon.md the strongest, repeatedly supported in vivo substrate is H4K16 PMID:34014972 Approximately 60% of cellular H4 K16Ac in S. cerevisiae
GO:0036408 histone H3K14 acetyltransferase activity	IDA PMID:12626510 Sas4 and Sas5 are required for the histone acetyltransferase...	NEW	Summary: SAS2 acetylates histone H3K14 in direct in vitro assays with the recombinant and purified SAS complex; this is a supported secondary substrate relative to the dominant in vivo H4K16 activity. Reason: UniProt functionally describes SAS2 as acetylating Lys-16 of histone H4 and Lys-14 of histone H3, and PMID:12626510 provides direct in vitro biochemical evidence for both H4K16 and H3K14 acetylation by recombinant and purified SAS complex. The falcon deep-research report flagged that H4K16 is the dominant in vivo substrate in its retrieved excerpts, so the H3K14 activity is included conservatively as a secondary substrate rather than promoted above the H4K16 activity. Supporting Evidence: PMID:12626510 The recombinant SAS complex acetylates H4 lysine 16 and H3 lysine 14 PMID:12626510 a purified SAS complex from yeast shows similar activity and specificity
GO:0035267 NuA4 histone acetyltransferase complex	IBA GO_REF:0000033	REMOVE	Summary: SAS2 is annotated as part of NuA4 HAT complex by IBA. However, UniProt and primary literature clearly state SAS2 is part of the SAS complex (with SAS4 and SAS5), not NuA4. NuA4 is a different HAT complex with distinct subunits and functions. This is an incorrect phylogenetic inference. Reason: SAS2 is definitively a component of the SAS acetyltransferase complex, not NuA4. UniProt CC field: "Component of the SAS complex, at least composed of SAS2, SAS4 and SAS5". GO:0033255 SAS acetyltransferase complex is the correct complex annotation for this gene. IBA inference incorrectly assigned SAS2 to NuA4. Propagation Review Root cause: PROPAGATION BAD Failure modes: WRONG ORTHOLOG OR PARALOG COMPARTMENT OR COMPLEX MISMATCH Sources checked: PANTHER:PTN007449682 · PTN007449682 SUPPORTS SOURCE BUT NOT TARGET PTN007449682 transfers NuA4 membership from KAT5/TIP60 IBD seeds in PTHR10615:SF219, the same subfamily that currently contains yeast Sas2 but excludes the real yeast NuA4 catalytic subunit Esa1 in SF218. Because PMID:22020126 treats ySas2 as the yeast KAT8/MOF ortholog, the remedy is Sas2 re-placement toward SF82/KAT8 or an IRD/NOT on the yeast Sas2 branch for NuA4 complex membership, not simply restricting PTN007449682. Supporting Evidence: PMID:11731479 The yeast SAS (something about silencing) protein complex contains a MYST-type putative acetyltransferase and functions with chromatin assembly factor ASF1. PMID:11731480 The silencing complex SAS-I links histone acetylation to the assembly of repressed chromatin by CAF-I and Asf1 in Saccharomyces cerevisiae. file:yeast/SAS2/SAS2-deep-research-falcon.md This distinguishes it from related but different MYST proteins such as Esa1, Sas3, and metazoan MOF homologs file:interpro/panther/PTHR10615/PTHR10615-paint.tsv PTHR10615 PTN007449682 GO:0035267 C IBD false FB:FBgn0026080\|MGI:MGI:1932051\|UniProtKB:Q92993 taxon:33154 20231108 PMID:22020126 this lysine autoacetylation on yEsa1, hMOF and its yeast orthologue, ySas2 (KAT8) occurs in solution and is required for acetylation and protein substrate binding in vitro
GO:0000781 chromosome, telomeric region	IEA GO_REF:0000108	KEEP AS NON CORE	Summary: SAS2 is involved in transcriptional silencing at telomeres and subtelomeres, making localization to telomeric regions biologically relevant. However, this is inferred from GO:0031509 (subtelomeric heterochromatin formation) via IEA logical inference. The annotation is supported by functional evidence of SAS2 involvement in telomeric silencing. Reason: While SAS2 is functional at telomeric and subtelomeric regions, the primary molecular function is histone acetyltransferase activity and the biological process is silencing/heterochromatin formation. Chromosomal localization is secondary and could be misleading without context. The IEA inference is logically sound but the term is too broad (chromosome, telomeric region encompasses many genes without specific roles there).
GO:0004402 histone acetyltransferase activity	IEA GO_REF:0000120	ACCEPT	Summary: SAS2 possesses histone acetyltransferase activity as its primary biochemical function. The IEA annotation via InterPro and RHEA is appropriate for this conserved domain function, representing the general HAT activity class. Reason: GO:0004402 (histone acetyltransferase activity) is a general term that encompasses SAS2s specific H4K16 and H3K14 acetylation activities. The IEA is supported by InterPro domain mapping and direct enzymatic characterization. This is appropriate as a parent term to the more specific H4K16 acetyltransferase function. Supporting Evidence: PMID:12626510 Here we show that recombinant Sas2 has HAT activity that absolutely requires Sas4 and is stimulated by Sas5
GO:0005634 nucleus	IEA GO_REF:0000044	ACCEPT	Summary: SAS2 is localized to the nucleus based on UniProt subcellular location annotation, consistent with its function in chromatin regulation. This IEA from UniProtKB subcellular location is reliable. Reason: SAS2 is documented as localized to nucleus and cytoplasm per UniProt (ECO:0000269\|PubMed:14562095). The nucleus annotation is appropriate and supported by experimental evidence. IEA is justified for this standard cellular compartment annotation. Supporting Evidence: file:yeast/SAS2/SAS2-deep-research-falcon.md GFP-tagged Sas2 predominantly stains the nucleus, including the nucleolus.
GO:0005737 cytoplasm	IEA GO_REF:0000044	KEEP AS NON CORE	Summary: SAS2 is localized to both nucleus and cytoplasm according to UniProt. The cytoplasmic localization may reflect either protein processing or a minor cytoplasmic pool, but the primary functional compartment is nuclear. Reason: UniProt documents both nucleus and cytoplasm localization with evidence from PMID:14562095 (large-scale localization study), so the annotation is retained rather than removed. However, the falcon deep research synthesis consistently characterizes Sas2 as a chromatin-bound nuclear protein (nucleus including the nucleolus, with ChIP association to rDNA) and provides no evidence for a functional cytoplasmic role. The cytoplasmic pool is therefore demoted to non-core: SAS2 executes its histone acetyltransferase function exclusively in the nucleus on chromatin. Supporting Evidence: file:yeast/SAS2/SAS2-deep-research-falcon.md Sas2 is a chromatin-bound nuclear protein; GFP-tagged Sas2 predominantly stains the nucleus, including the nucleolus.
GO:0006325 chromatin organization	IEA GO_REF:0000043	MARK AS OVER ANNOTATED	Summary: SAS2 participates in chromatin organization through its HAT activity, affecting histone modifications and chromatin structure. The IEA from UniProtKB keywords was retired upstream and was broader than the direct heterochromatin terms already accepted for SAS2. Reason: GO:0006325 is a broad chromatin-organization parent of the more specific subtelomeric and silent mating-type heterochromatin rows that SAS2 already carries with experimental support. The retired keyword row added no extra functional specificity. Supporting Evidence: PMID:34014972 H4 K16Ac appears in chromatin immediately upon replication. Importantly, this increase depends on the presence of functional SAS-I complex.
GO:0006351 DNA-templated transcription	IEA GO_REF:0000043	MARK AS OVER ANNOTATED	Summary: SAS2 indirectly affects transcription through chromatin modifications, but the primary function is histone modification at specific loci (silencing at telomeres, HML). The IEA from keywords likely reflects the broad but indirect transcriptional effects of HAT activity. Reason: While SAS2 affects chromatin state and can indirectly influence transcription, the specific functional role is transcriptional silencing at telomeres/subtelomeres, not general transcription. GO:0006351 is too general and suggests a broader transcriptional role than what is known. Transcriptional regulation (GO:0006355) is more mechanistically accurate than the process of transcription itself.
GO:0006355 regulation of DNA-templated transcription	IEA GO_REF:0000002	ACCEPT	Summary: SAS2 regulates transcription by acetylating histones at silenced loci (telomeres, HML), repressing transcription in those regions while potentially permitting transcription elsewhere. GO:0006355 appropriately captures this regulatory role without implying general transcriptional activation. Reason: SAS2 regulates transcription through histone acetylation-mediated chromatin organization. The GO:0006355 term is appropriately intermediate between general transcription (GO:0006351) and specific processes (silencing). IBA/IEA inference from HAT domain function is justified.
GO:0008270 zinc ion binding	IEA GO_REF:0000043	ACCEPT	Summary: SAS2 contains a MYST-type HAT domain with a C2HC zinc-finger motif essential for catalytic activity. Zinc binding is a structural requirement for HAT activity, documented in UniProt features. Reason: UniProt documents zinc finger structure: "ZN_FING 100..126: C2HC MYST-type". Zinc coordination is essential for the catalytic mechanism of MYST-family acetyltransferases. IEA from zinc keyword is supported by structural annotations.
GO:0010468 regulation of gene expression	IEA GO_REF:0000117	MARK AS OVER ANNOTATED	Summary: This is a very broad parent term encompassing the effects of histone acetylation on gene expression regulation. While technically correct, it is less specific than the actual biological processes SAS2 participates in. Reason: GO:0010468 is overly broad and abstract. SAS2s known roles are more specifically: (1) subtelomeric heterochromatin formation (GO:0031509), (2) silent mating-type cassette heterochromatin formation (GO:0030466), and (3) transcription regulation via histone modification. The more specific terms (GO:0031509, GO:0030466) should be preferred.
GO:0016740 transferase activity	IEA GO_REF:0000043	MARK AS OVER ANNOTATED	Summary: SAS2 catalyzes acetyl group transfer from acetyl-CoA to lysine residues on histones. GO:0016740 transferase activity is the parent term for all acetyltransferase activities. Reason: GO:0016740 is a very broad parent of the accepted acetyltransferase, protein-lysine-acetyltransferase, histone acetyltransferase, and H4K16 acetyltransferase rows. The retired keyword row added no useful specificity beyond those more exact functions.
GO:0016746 acyltransferase activity	IEA GO_REF:0000043	MARK AS OVER ANNOTATED	Summary: Acetyltransferases are a subset of acyltransferases that transfer the acetyl group (an acyl group) from acetyl-CoA. This is a parent term that appropriately classifies the enzyme. Reason: GO:0016746 is a generic parent of SAS2's accepted acetyltransferase and histone acetyltransferase activities. The retired keyword row was true only at an unhelpfully broad level and was superseded by more specific catalytic rows.
GO:0046872 metal ion binding	IEA GO_REF:0000043	MARK AS OVER ANNOTATED	Summary: SAS2 binds zinc ions as an essential cofactor for catalytic function. GO:0046872 is the parent term for all metal ion binding activities including zinc binding. Reason: GO:0046872 is a broad parent of GO:0008270 zinc ion binding, which SAS2 already carries from both a live RCA row and a retired keyword row. The retired metal-ion keyword row was redundant with that more precise zinc-binding function.
GO:0061733 protein-lysine-acetyltransferase activity	IEA GO_REF:0000120	ACCEPT	Summary: SAS2 catalyzes the transfer of acetyl groups from acetyl-CoA to lysine residues on protein substrates (histones). This is the direct enzymatic activity captured by GO:0061733. Reason: GO:0061733 is mechanistically accurate for SAS2s enzymatic function. UniProt documents EC number 2.3.1.48 (protein-lysine-acetyltransferase), and PMID:12626510 demonstrates lysine acetylation. This term is more specific than general transferase activity but broader than histone-specific acetyltransferases.
GO:0005515 protein binding	IPI PMID:11731480 The silencing complex SAS-I links histone acetylation to the...	REMOVE	Summary: SAS2 interacts with SAS4, SAS5, ASF1, and other chromatin factors. However, generic protein binding is not informative and masks the specific functional interactions (complex assembly, substrate presentation, etc.). Reason: GO:0005515 (protein binding) is a vague annotation that provides minimal functional information. The underlying IPI data references protein-protein interactions identified in biochemical purifications and mass spectrometry. More informative would be direct component annotations of specific protein complexes (GO:0033255 SAS acetyltransferase complex). Individual protein binding events should not be annotated to the generic protein binding term. Supporting Evidence: PMID:11731480 The silencing complex SAS-I links histone acetylation to the assembly of repressed chromatin by CAF-I and Asf1 in Saccharomyces cerevisiae. PMID:11731479 The yeast SAS (something about silencing) protein complex contains a MYST-type putative acetyltransferase and functions with chromatin assembly factor ASF1.
GO:0005515 protein binding	IPI PMID:16554755 Global landscape of protein complexes in the yeast Saccharom...	REMOVE	Summary: Generic protein binding annotation from global protein complex inventory. Reason: This retired IPI annotation from the Krogan et al. global protein complex survey identifies SAS2 component membership in the SAS complex, which is better captured by GO:0033255 than by a vague protein binding annotation. Supporting Evidence: PMID:16554755 We used tandem affinity purification to process 4,562 different tagged proteins of the yeast Saccharomyces cerevisiae PMID:11731479 Here we identify a ~450-kD SAS complex containing Sas2p, Sas4p, and the tf2f-related Sas5 protein PMID:11731480 Sas2 was found to interact with Cac1, the largest subunit of Saccharomyces cerevisiae chromatin assembly factor-I (CAF-I), and with the nucleosome assembly factor Asf1.
GO:0005515 protein binding	IPI PMID:21179020 Defining the budding yeast chromatin-associated interactome.	REMOVE	Summary: Generic protein binding annotation from chromatin-associated interactome data. Reason: The IPI evidence documents SAS2 as component of chromatin-associated complexes. Complex membership is better represented by GO:0033255 than generic protein binding. Supporting Evidence: PMID:21179020 Defining the budding yeast chromatin-associated interactome.
GO:0005515 protein binding	IPI PMID:37968396 The social and structural architecture of the yeast protein ...	REMOVE	Summary: Generic Sas2-Sas4 protein binding from a broad yeast interactome study. Reason: The high-throughput GFP pull-down interactome is consistent with Sas2 and Sas4 acting together, but the generic GO:0005515 assertion is less informative than the direct SAS acetyltransferase complex rows. Supporting Evidence: PMID:37968396 we set out to generate a substantially complete interactome of all proteins present in an organism in a given state
GO:0008270 zinc ion binding	RCA PMID:30358795 The cellular economy of the Saccharomyces cerevisiae zinc pr...	ACCEPT	Summary: Sas2 carries a C2HC MYST-type zinc-finger feature consistent with the reviewed computational zinc-binding call. Reason: RCA is reviewed computational analysis, not direct biochemical measurement, and PMID:30358795 describes its yeast zinc-proteome set as a domain/motif bioinformatics analysis. The SGD row is still plausible because Sas2 has a PROSITE-predicted C2HC MYST-type zinc finger in its catalytic MYST domain; current UniProt has dropped the older keyword-derived zinc-binding IEA, while this SGD RCA assertion persists. Supporting Evidence: PMID:30358795 identified using a bioinformatics analysis that combined global domain searches with local motif searches file:yeast/SAS2/SAS2-uniprot.txt FT ZN_FING 100..126 FT /note="C2HC MYST-type"
GO:0031509 subtelomeric heterochromatin formation	IDA PMID:11731479 The yeast SAS (something about silencing) protein complex co...	ACCEPT	Summary: SAS2 is experimentally demonstrated to be required for transcriptional silencing and heterochromatin formation at subtelomeric regions and HML locus. This IDA is mechanistically well-characterized and represents a core function of SAS2. Reason: PMID:11731479 demonstrates SAS2 function with chromatin assembly factor ASF1 in silencing. The role in subtelomeric heterochromatin formation is well-established. IDA is appropriate evidence code for this experimentally characterized process. Supporting Evidence: PMID:11731479 The something about silencing (Sas) 2 protein of Saccharomyces cerevisiae, a member of the MYST (MOZ, Ybf2/Sas3, Sas2, and TIP60) acetyltransferase family, promotes silencing at HML and telomeres PMID:34014972 In the absence of SAS-I, H4 K16Ac levels are reduced, which leads to the spreading of the SIR complex from the telomeres into subtelomeric regions and to inappropriate silencing of genes that are located in these regions.
GO:0000785 chromatin	IDA PMID:11731479 The yeast SAS (something about silencing) protein complex co...	ACCEPT	Summary: SAS2 localizes to and functions within chromatin as part of histone acetylation complexes. The chromatin component annotation reflects the cellular compartment where SAS2 executes its function. Reason: SAS2 is retained at chromatin by deferring to SGD's full-text curation of PMID:11731479; the local cache is abstract-only and shows SAS-I/Asf1 coupling but does not itself describe the chromatin-localization assay. The chromatin assignment also agrees with later full-text evidence that H4 K16Ac appears in chromatin in a functional SAS-I-dependent manner immediately after DNA replication. Supporting Evidence: PMID:11731479 the SAS complex is found to interact with chromatin assembly factor Asf1p PMID:34014972 that H4 K16Ac appears in chromatin immediately upon replication. Importantly, this increase depends on the presence of functional SAS-I complex
GO:0030466 silent mating-type cassette heterochromatin formation	IMP PMID:27655944 Donor Preference Meets Heterochromatin; Moonlighting Activit...	ACCEPT	Summary: SAS2 is shown through mutant/deletion studies to be involved in maintaining transcriptional silencing at the silent mating-type locus (HML). This IMP evidence characterizes a specific SAS2 function in heterochromatin establishment/maintenance. Reason: SGD curates this silent-mating-type IMP row to PMID:27655944; the local cache is abstract-only and does not mention Sas2, so the review defers to SGD's full-text curation here. The assignment agrees with UniProt's broader statement that the SAS complex is involved in transcriptional silencing at telomeres and HML. Supporting Evidence: file:yeast/SAS2/SAS2-uniprot.txt The complex is involved in transcriptional silencing at telomeres and at HML locus.
GO:0004402 histone acetyltransferase activity	IDA PMID:12626510 Sas4 and Sas5 are required for the histone acetyltransferase...	ACCEPT	Summary: Direct biochemical demonstration of SAS2 HAT activity through in vitro acetyltransferase assays with purified recombinant and native SAS complex. This IDA evidence is strong and mechanistic. Reason: PMID:12626510 provides direct experimental evidence of HAT activity through enzyme assay of purified SAS complex containing SAS2. This is the gold standard IDA evidence. The annotation is accurate and well-supported. Supporting Evidence: PMID:12626510 Recombinant Sas2 has HAT activity that absolutely requires Sas4 and is stimulated by Sas5
GO:0016407 acetyltransferase activity	IDA PMID:11731479 The yeast SAS (something about silencing) protein complex co...	ACCEPT	Summary: SAS2 is demonstrated to have acetyltransferase activity through biochemical characterization. GO:0016407 is the parent term for histone acetyltransferase activity, appropriately classifying SAS2s enzymatic function. Reason: Acetyltransferase activity is well-established for SAS2. IDA from PMID:11731479 (purification and characterization of SAS complex with Sas2 as MYST-type acetyltransferase) provides direct evidence. This is an appropriate parent term. Supporting Evidence: PMID:11731479 Mutations in the conserved acetyl-CoA binding motif of Sas2p are shown to disrupt the ability of Sas2p to mediate the silencing at HML and telomeres
GO:0033255 SAS acetyltransferase complex	IDA PMID:12626510 Sas4 and Sas5 are required for the histone acetyltransferase...	ACCEPT	Summary: SAS2 is the catalytic core of the SAS acetyltransferase complex, composed minimally of SAS2, SAS4, and SAS5. IDA evidence from complex purification and functional assays directly demonstrates SAS2 component membership. Reason: SAS2 is a core component of the SAS complex, definitively established through biochemistry. PMID:12626510 characterizes the complex composition and function. GO:0033255 is the appropriate term for this complex, and SAS2 must be annotated as part_of this complex. Supporting Evidence: PMID:12626510 Sas2 forms a complex with Sas4 and Sas5, which are required for its silencing function file:yeast/SAS2/SAS2-deep-research-falcon.md Sas2 acts in a nuclear complex termed SAS-I, composed of Sas2, Sas4, and Sas5, which coimmunoprecipitate and coelute as a ~220 kDa complex.
GO:0033255 SAS acetyltransferase complex	IPI PMID:15788653 Nuclear import of the histone acetyltransferase complex SAS-...	ACCEPT	Summary: SAS2 nuclear import associated with complex assembly documented by IPI evidence from interaction studies. Reason: PMID:15788653 documents nuclear import of the SAS-I complex (SAS complex), providing complementary IPI evidence of SAS2 participation. Multiple independent lines of evidence (IDA and IPI) support SAS2 as component of GO:0033255. Supporting Evidence: PMID:15788653 Sas2p, the histone acetyltransferase subunit of SAS-I, forms a complex with Sas4p and Sas5p
GO:0005515 protein binding	IPI PMID:11731480 The silencing complex SAS-I links histone acetylation to the...	REMOVE	Summary: Generic protein binding annotation for the Sas2-Sas4 interaction. Reason: This IntAct row records the biochemically important Sas2-Sas4 interaction within SAS-I, but GO:0005515 is an uninformative molecular-function assertion. The same evidence is better represented by the accepted SAS acetyltransferase complex rows, which capture the functional consequence of the interaction. Supporting Evidence: PMID:11731480 Sas2 was found in a nuclear protein complex that included Sas4 and Sas5
GO:0005515 protein binding	IPI PMID:11731480 The silencing complex SAS-I links histone acetylation to the...	REMOVE	Summary: Generic protein binding annotation for the Sas2-Cac1/CAF-I interaction. Reason: This IntAct row records the Sas2 interaction with Cac1/Rlf2, the CAF-I largest subunit. The bare GO:0005515 term still does not describe the activity of Sas2, but the SAS acetyltransferase complex row does not cover this CAF-I recruitment connection; preserve that distinction in notes rather than retaining a generic binding molecular-function assertion. Supporting Evidence: PMID:11731480 interact with Cac1, the largest subunit of Saccharomyces cerevisiae chromatin
GO:0005515 protein binding	IPI PMID:11731480 The silencing complex SAS-I links histone acetylation to the...	REMOVE	Summary: This stale pre-refresh source row represented the Q99314-supported PMID:11731480 IntAct assertion. The specific source row is absent from the current GOA TSV and the generic protein-binding term is not informative. Reason: This vanished Q99314-supported GOA source is retained as a retired historical row. Its GO:0005515 term is the same uninformative generic binding assertion as the other IntAct rows and does not improve on the accepted SAS acetyltransferase complex membership. Supporting Evidence: PMID:11731480 Sas2 was found in a nuclear protein complex that included Sas4 and Sas5 PMID:12626510 Sas2 forms a complex with Sas4 and Sas5
GO:0005515 protein binding	IPI PMID:21179020 Defining the budding yeast chromatin-associated interactome.	REMOVE	Summary: Generic Sas2-Sas4 protein binding from the chromatin-associated interactome. Reason: The interactome evidence is consistent with Sas2 and Sas4 acting together in the SAS acetyltransferase complex, but the generic GO:0005515 assertion is not itself informative. The row should give way to the specific complex membership captured elsewhere in GOA. Supporting Evidence: PMID:21179020 Defining the budding yeast chromatin-associated interactome.
GO:0005515 protein binding	IPI PMID:21179020 Defining the budding yeast chromatin-associated interactome.	REMOVE	Summary: This stale pre-refresh PMID:21179020 source row represented a high-throughput Q99314-supported Sas2 association. The row is no longer present in the current GOA TSV and, even if current, would only assert generic protein binding rather than Sas2 catalytic function or SAS complex membership. Reason: The 2026 forced GOA refresh dropped this specific Q99314-supported source, so it is retained only as a retired historical record. Its GO:0005515 term is the same uninformative generic binding assertion as the retained IntAct rows from the chromatin-associated interactome. Supporting Evidence: PMID:21179020 This mChIP study of the chromatin interactome resulted in the detection of 2966 high confidence protein associations with 724 distinct preys.
GO:0033255 SAS acetyltransferase complex	IPI PMID:11731480 The silencing complex SAS-I links histone acetylation to the...	ACCEPT	Summary: ComplexPortal curates Sas2 as part of the SAS acetyltransferase complex. Reason: GO:0033255 is the correct complex term for Sas2. Meijsing and Ehrenhofer-Murray showed that Sas2, Sas4, and Sas5 form SAS-I, and the ComplexPortal IPI row is a current independent curation of that same complex membership. Supporting Evidence: PMID:11731480 Sas2 was found in a nuclear protein complex that included Sas4 and Sas5
GO:0061733 protein-lysine-acetyltransferase activity	EXP PMID:22020126 MYST protein acetyltransferase activity requires active site...	ACCEPT	Summary: UniProt experimentally supports the generic protein-lysine-acetyltransferase activity of Sas2. Reason: Sas2 is a MYST protein lysine acetyltransferase: its H4K16 and H3K14 histone activities are substrate-specific instances of GO:0061733, and the Yuan et al. active-site autoacetylation paper directly tested yeast Sas2 acetyltransferase activity in vitro. Supporting Evidence: PMID:22020126 lysine autoacetylation on yEsa1, hMOF and its yeast orthologue, ySas2 (KAT8) occurs in solution and is required for acetylation and protein substrate binding in vitro

Gene Description

Existing Annotations Review

Core Functions

SAS2 acetylates histone H4 at lysine 16 and histone H3 at lysine 14, functioning as the catalytic subunit of the SAS complex to establish and maintain transcriptional silencing at telomeres and subtelomeres while also limiting Sir-complex spreading at some telomeric boundaries.

References

Suggested Questions for Experts

Deep Research

Falcon

SGD

SGD gene description for SAS2 (yeast)

📚 Additional Documentation

Notes

Curation Review

Review Summary

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