Sus1 is a conserved small subunit of the SAGA transcription coactivator and the TREX-2 mRNA export complex. It connects transcription-associated chromatin regulation with nuclear mRNA export. Within the SAGA deubiquitination module it supports complex assembly and histone H2B deubiquitination by the catalytic subunit; it is not itself a histone deubiquitinase.
Reason: Fission yeast SAGA purification establishes Sus1 membership. In sgf73 deletion mutants, Sus1, Sgf11 and Ubp8 are absent from SAGA purifications, placing Sus1 within the Sgf73-anchored deubiquitination module. The conserved composition is also supported by the earlier target SAGA study.
IDA PMID:19056896 The S. pombe SAGA complex controls the switch from prolifera...
ACCEPT
Summary: SAGA complex is supported.
Reason: Fission yeast SAGA purification establishes Sus1 membership. In sgf73 deletion mutants, Sus1, Sgf11 and Ubp8 are absent from SAGA purifications, placing Sus1 within the Sgf73-anchored deubiquitination module. The conserved composition is also supported by the earlier target SAGA study.
Reason: Fission yeast SAGA purification establishes Sus1 membership. In sgf73 deletion mutants, Sus1, Sgf11 and Ubp8 are absent from SAGA purifications, placing Sus1 within the Sgf73-anchored deubiquitination module. The conserved composition is also supported by the earlier target SAGA study.
IPI PMID:19056896 The S. pombe SAGA complex controls the switch from prolifera...
ACCEPT
Summary: SAGA complex is supported.
Reason: Fission yeast SAGA purification establishes Sus1 membership. In sgf73 deletion mutants, Sus1, Sgf11 and Ubp8 are absent from SAGA purifications, placing Sus1 within the Sgf73-anchored deubiquitination module. The conserved composition is also supported by the earlier target SAGA study.
IPI PMID:29079657 TORC1 and TORC2 converge to regulate the SAGA co-activator i...
ACCEPT
Summary: SAGA complex is supported.
Reason: Fission yeast SAGA purification establishes Sus1 membership. In sgf73 deletion mutants, Sus1, Sgf11 and Ubp8 are absent from SAGA purifications, placing Sus1 within the Sgf73-anchored deubiquitination module. The conserved composition is also supported by the earlier target SAGA study.
Reason: The reviewed primary evidence establishes nuclear SAGA and nuclear-pore export functions, but does not resolve a functional cytoplasmic or P-body pool of fission yeast Sus1. The automatic localization mapping is plausible but needs the underlying localization experiment or a specific justified transfer.
Biochemical analyses show that Sus1 interacts with SAGA, a large intranuclear histone acetylase complex involved in transcription initiation, and with the Sac3-Thp1 complex, which functions in mRNA export with specific nuclear pore proteins at the nuclear basket.
Summary: transcription coactivator activity is supported.
Reason: Sus1 is a subunit of the transcriptional coactivator SAGA. Its conserved role is supported by target complex purification and by transcription assays and promoter recruitment in characterized budding yeast Sus1; it does not imply Sus1 possesses an independent histone-modifying catalytic activity.
Biochemical analyses show that Sus1 interacts with SAGA, a large intranuclear histone acetylase complex involved in transcription initiation, and with the Sac3-Thp1 complex, which functions in mRNA export with specific nuclear pore proteins at the nuclear basket.
Summary: transcription coactivator activity is supported.
Reason: Sus1 is a subunit of the transcriptional coactivator SAGA. Its conserved role is supported by target complex purification and by transcription assays and promoter recruitment in characterized budding yeast Sus1; it does not imply Sus1 possesses an independent histone-modifying catalytic activity.
Biochemical analyses show that Sus1 interacts with SAGA, a large intranuclear histone acetylase complex involved in transcription initiation, and with the Sac3-Thp1 complex, which functions in mRNA export with specific nuclear pore proteins at the nuclear basket.
Reason: Characterized Sus1 participates in the Sac3-Thp1/TREX-2 export machinery and concentrates at nuclear pores; sus1 mutants impair nuclear mRNA export. The conserved Sus1 subfamily and curated phylogenetic/orthology assertions support transfer of this functional complex context to fission yeast.
Biochemical analyses show that Sus1 interacts with SAGA, a large intranuclear histone acetylase complex involved in transcription initiation, and with the Sac3-Thp1 complex, which functions in mRNA export with specific nuclear pore proteins at the nuclear basket.
Reason: Characterized Sus1 participates in the Sac3-Thp1/TREX-2 export machinery and concentrates at nuclear pores; sus1 mutants impair nuclear mRNA export. The conserved Sus1 subfamily and curated phylogenetic/orthology assertions support transfer of this functional complex context to fission yeast.
Biochemical analyses show that Sus1 interacts with SAGA, a large intranuclear histone acetylase complex involved in transcription initiation, and with the Sac3-Thp1 complex, which functions in mRNA export with specific nuclear pore proteins at the nuclear basket.
Reason: Characterized Sus1 participates in the Sac3-Thp1/TREX-2 export machinery and concentrates at nuclear pores; sus1 mutants impair nuclear mRNA export. The conserved Sus1 subfamily and curated phylogenetic/orthology assertions support transfer of this functional complex context to fission yeast.
Biochemical analyses show that Sus1 interacts with SAGA, a large intranuclear histone acetylase complex involved in transcription initiation, and with the Sac3-Thp1 complex, which functions in mRNA export with specific nuclear pore proteins at the nuclear basket.
Reason: The reviewed primary evidence establishes nuclear SAGA and nuclear-pore export functions, but does not resolve a functional cytoplasmic or P-body pool of fission yeast Sus1. The automatic localization mapping is plausible but needs the underlying localization experiment or a specific justified transfer.
Biochemical analyses show that Sus1 interacts with SAGA, a large intranuclear histone acetylase complex involved in transcription initiation, and with the Sac3-Thp1 complex, which functions in mRNA export with specific nuclear pore proteins at the nuclear basket.
GO:0006357 regulation of transcription by RNA polymerase II
EXP PMID:21642955 Tra1 has specific regulatory roles, rather than global funct...
ACCEPT
Summary: regulation of transcription by RNA polymerase II is supported.
Reason: Sus1 is a subunit of the transcriptional coactivator SAGA. Its conserved role is supported by target complex purification and by transcription assays and promoter recruitment in characterized budding yeast Sus1; it does not imply Sus1 possesses an independent histone-modifying catalytic activity. The original PMID:21642955 annotation is retained at its stated evidential scope; accessible source text and the independent evidence cited here are considered together.
Biochemical analyses show that Sus1 interacts with SAGA, a large intranuclear histone acetylase complex involved in transcription initiation, and with the Sac3-Thp1 complex, which functions in mRNA export with specific nuclear pore proteins at the nuclear basket.
GO:0006357 regulation of transcription by RNA polymerase II
IBA GO_REF:0000033
ACCEPT
Summary: regulation of transcription by RNA polymerase II is supported.
Reason: Sus1 is a subunit of the transcriptional coactivator SAGA. Its conserved role is supported by target complex purification and by transcription assays and promoter recruitment in characterized budding yeast Sus1; it does not imply Sus1 possesses an independent histone-modifying catalytic activity.
Biochemical analyses show that Sus1 interacts with SAGA, a large intranuclear histone acetylase complex involved in transcription initiation, and with the Sac3-Thp1 complex, which functions in mRNA export with specific nuclear pore proteins at the nuclear basket.
GO:0006357 regulation of transcription by RNA polymerase II
NAS PMID:19056896 The S. pombe SAGA complex controls the switch from prolifera...
ACCEPT
Summary: regulation of transcription by RNA polymerase II is supported.
Reason: Sus1 is a subunit of the transcriptional coactivator SAGA. Its conserved role is supported by target complex purification and by transcription assays and promoter recruitment in characterized budding yeast Sus1; it does not imply Sus1 possesses an independent histone-modifying catalytic activity.
Biochemical analyses show that Sus1 interacts with SAGA, a large intranuclear histone acetylase complex involved in transcription initiation, and with the Sac3-Thp1 complex, which functions in mRNA export with specific nuclear pore proteins at the nuclear basket.
GO:0006368 transcription elongation by RNA polymerase II
IEA GO_REF:0000104
ACCEPT
Summary: transcription elongation by RNA polymerase II is supported.
Reason: Sus1 links SAGA-dependent transcription with export; the curated homology assertion of participation in elongation is compatible with its transcription-associated chromatin role. This is an accessory contribution to RNA polymerase II transcription, not RNA polymerase activity.
Biochemical analyses show that Sus1 interacts with SAGA, a large intranuclear histone acetylase complex involved in transcription initiation, and with the Sac3-Thp1 complex, which functions in mRNA export with specific nuclear pore proteins at the nuclear basket.
Reason: Characterized Sus1 participates in the Sac3-Thp1/TREX-2 export machinery and concentrates at nuclear pores; sus1 mutants impair nuclear mRNA export. The conserved Sus1 subfamily and curated phylogenetic/orthology assertions support transfer of this functional complex context to fission yeast.
Biochemical analyses show that Sus1 interacts with SAGA, a large intranuclear histone acetylase complex involved in transcription initiation, and with the Sac3-Thp1 complex, which functions in mRNA export with specific nuclear pore proteins at the nuclear basket.
Summary: poly(A)+ mRNA export from nucleus is supported.
Reason: Characterized Sus1 participates in the Sac3-Thp1/TREX-2 export machinery and concentrates at nuclear pores; sus1 mutants impair nuclear mRNA export. The conserved Sus1 subfamily and curated phylogenetic/orthology assertions support transfer of this functional complex context to fission yeast.
Biochemical analyses show that Sus1 interacts with SAGA, a large intranuclear histone acetylase complex involved in transcription initiation, and with the Sac3-Thp1 complex, which functions in mRNA export with specific nuclear pore proteins at the nuclear basket.
Summary: transcription initiation-coupled chromatin remodeling is supported.
Reason: Sus1 supports the SAGA histone H2B deubiquitination module through its association with Ubp8 and Sgf11. This establishes a conserved contribution to chromatin regulation at transcription activation; the catalytic deubiquitinase is a separate subunit.
Purification of the S. pombe SAGA complex showed that its subunit composition is identical to that of Saccharomyces cerevisiae.
GO:0045893 positive regulation of DNA-templated transcription
IEA GO_REF:0000120
ACCEPT
Summary: positive regulation of DNA-templated transcription is supported.
Reason: Sus1 is a subunit of the transcriptional coactivator SAGA. Its conserved role is supported by target complex purification and by transcription assays and promoter recruitment in characterized budding yeast Sus1; it does not imply Sus1 possesses an independent histone-modifying catalytic activity.
Biochemical analyses show that Sus1 interacts with SAGA, a large intranuclear histone acetylase complex involved in transcription initiation, and with the Sac3-Thp1 complex, which functions in mRNA export with specific nuclear pore proteins at the nuclear basket.
GO:0045944 positive regulation of transcription by RNA polymerase II
ISO GO_REF:0000024
ACCEPT
Summary: positive regulation of transcription by RNA polymerase II is supported.
Reason: Sus1 is a subunit of the transcriptional coactivator SAGA. Its conserved role is supported by target complex purification and by transcription assays and promoter recruitment in characterized budding yeast Sus1; it does not imply Sus1 possesses an independent histone-modifying catalytic activity.
Biochemical analyses show that Sus1 interacts with SAGA, a large intranuclear histone acetylase complex involved in transcription initiation, and with the Sac3-Thp1 complex, which functions in mRNA export with specific nuclear pore proteins at the nuclear basket.
Summary: transcription export complex 2 is supported.
Reason: Characterized Sus1 participates in the Sac3-Thp1/TREX-2 export machinery and concentrates at nuclear pores; sus1 mutants impair nuclear mRNA export. The conserved Sus1 subfamily and curated phylogenetic/orthology assertions support transfer of this functional complex context to fission yeast.
Biochemical analyses show that Sus1 interacts with SAGA, a large intranuclear histone acetylase complex involved in transcription initiation, and with the Sac3-Thp1 complex, which functions in mRNA export with specific nuclear pore proteins at the nuclear basket.
Summary: transcription export complex 2 is supported.
Reason: Characterized Sus1 participates in the Sac3-Thp1/TREX-2 export machinery and concentrates at nuclear pores; sus1 mutants impair nuclear mRNA export. The conserved Sus1 subfamily and curated phylogenetic/orthology assertions support transfer of this functional complex context to fission yeast.
Biochemical analyses show that Sus1 interacts with SAGA, a large intranuclear histone acetylase complex involved in transcription initiation, and with the Sac3-Thp1 complex, which functions in mRNA export with specific nuclear pore proteins at the nuclear basket.
Summary: transcription export complex 2 is supported.
Reason: Characterized Sus1 participates in the Sac3-Thp1/TREX-2 export machinery and concentrates at nuclear pores; sus1 mutants impair nuclear mRNA export. The conserved Sus1 subfamily and curated phylogenetic/orthology assertions support transfer of this functional complex context to fission yeast.
Biochemical analyses show that Sus1 interacts with SAGA, a large intranuclear histone acetylase complex involved in transcription initiation, and with the Sac3-Thp1 complex, which functions in mRNA export with specific nuclear pore proteins at the nuclear basket.
Reason: Sus1 supports the SAGA histone H2B deubiquitination module through its association with Ubp8 and Sgf11. This establishes a conserved contribution to chromatin regulation at transcription activation; the catalytic deubiquitinase is a separate subunit.
Reason: Sus1 supports the SAGA histone H2B deubiquitination module through its association with Ubp8 and Sgf11. This establishes a conserved contribution to chromatin regulation at transcription activation; the catalytic deubiquitinase is a separate subunit.
Biochemical analyses show that Sus1 interacts with SAGA, a large intranuclear histone acetylase complex involved in transcription initiation, and with the Sac3-Thp1 complex, which functions in mRNA export with specific nuclear pore proteins at the nuclear basket.
These computational predictions are reviewed separately from the GOA annotation set used for this review. The assessments below are from this project and do not constitute official GO annotations or endorsement by GO/UniProt. They are not included in the existing annotation review above.
Sus1 contributes to SAGA chromatin regulation and TREX-2-mediated nuclear mRNA export. Both predictions are supported but broader than the established chromatin-remodeling and polyadenylated-mRNA-export roles.
Review rationale: Mutant, localization and biochemical experiments in characterized budding yeast Sus1 establish an mRNA-export role through Sac3-Thp1/TREX-2. The fission yeast protein belongs to the conserved Sus1/ENY2 family, and curated phylogenetic and orthology annotations support the same complex role. GOA already records the more specific poly(A)+ mRNA export from nucleus (GO:0016973). The prediction is biologically supported through that justified comparative inference, with less transcript specificity.
Supporting Evidence:
PMID:14718168: "Biochemical analyses show that Sus1 interacts with SAGA, a large intranuclear histone acetylase complex involved in transcription initiation, and with the Sac3-Thp1 complex, which functions in mRNA export with specific nuclear pore proteins at the nuclear basket."
Review rationale: Fission yeast purification places Sus1 in SAGA, and characterized budding yeast Sus1 mutants establish participation in histone H2B deubiquitination and maintenance of histone H3 methylation. Transfer is justified by conserved Sus1 family identity and SAGA/DUB-module context; this is a noncatalytic contribution to chromatin regulation. GOA already specifies transcription initiation-coupled chromatin remodeling (GO:0045815). Generic chromatin organization is therefore supported but less precise.
Supporting Evidence:
PMID:19056896: "Purification of the S. pombe SAGA complex showed that its subunit composition is identical to that of Saccharomyces cerevisiae."
PMID:16855026: "We demonstrate that Sus1 is involved in the SAGA-dependent histone H2B deubiquitinylation and maintenance of normal H3 methylation levels."