Asr1 (SPCC126.07c, also called Pbr1) is a nuclear and cytosolic protein containing an N-terminal atypical RING finger and a PHD finger. Its cysteine- and histidine-rich zinc-finger architecture supports structural zinc binding and a conserved ubiquitin-ligase function inferred from budding-yeast Asr1. The physiological substrates and biological process controlled by Asr1 in fission yeast remain unresolved.
Summary: This ARBA assertion is not independent experimental evidence.
Reason: This ARBA assertion is not independent experimental evidence. The target has PHD/RING domains and its curated ortholog is an RNA-polymerase-associated E3 ligase, but that alone does not establish this specific fission-yeast localization or assembly. The exact claim requires target localization or complex evidence.
HDA PMID:16823372 ORFeome cloning and global analysis of protein localization ...
ACCEPT
Summary: The reviewed UniProt record cites the fission-yeast localization study PMID:16823372 for both cytoplasm and nucleus.
Reason: The reviewed UniProt record cites the fission-yeast localization study PMID:16823372 for both cytoplasm and nucleus. Retain the corresponding coarse localization; neither the RING/PHD architecture nor the budding-yeast polymerase interaction restricts the target to one compartment.
Supporting Evidence:
file:SCHPO/asr1/asr1-uniprot.txt
CC -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000269|PubMed:16823372}. Nucleus CC {ECO:0000269|PubMed:16823372}.
Summary: The reviewed UniProt record cites the fission-yeast localization study PMID:16823372 for both cytoplasm and nucleus.
Reason: The reviewed UniProt record cites the fission-yeast localization study PMID:16823372 for both cytoplasm and nucleus. Retain the corresponding coarse localization; neither the RING/PHD architecture nor the budding-yeast polymerase interaction restricts the target to one compartment.
Supporting Evidence:
file:SCHPO/asr1/asr1-uniprot.txt
CC -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000269|PubMed:16823372}. Nucleus CC {ECO:0000269|PubMed:16823372}.
Summary: The reviewed UniProt record cites the fission-yeast localization study PMID:16823372 for both cytoplasm and nucleus.
Reason: The reviewed UniProt record cites the fission-yeast localization study PMID:16823372 for both cytoplasm and nucleus. Retain the corresponding coarse localization; neither the RING/PHD architecture nor the budding-yeast polymerase interaction restricts the target to one compartment.
Supporting Evidence:
file:SCHPO/asr1/asr1-uniprot.txt
CC -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000269|PubMed:16823372}. Nucleus CC {ECO:0000269|PubMed:16823372}.
HDA PMID:16823372 ORFeome cloning and global analysis of protein localization ...
ACCEPT
Summary: The reviewed UniProt record cites the fission-yeast localization study PMID:16823372 for both cytoplasm and nucleus.
Reason: The reviewed UniProt record cites the fission-yeast localization study PMID:16823372 for both cytoplasm and nucleus. Retain the corresponding coarse localization; neither the RING/PHD architecture nor the budding-yeast polymerase interaction restricts the target to one compartment.
Supporting Evidence:
file:SCHPO/asr1/asr1-uniprot.txt
CC -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000269|PubMed:16823372}. Nucleus CC {ECO:0000269|PubMed:16823372}.
Summary: The ND biological-process root accurately represents that a target-specific physiological process remains undefined.
Reason: The ND biological-process root accurately represents that a target-specific physiological process remains undefined. Orthologous E3 activity and zinc-binding architecture do not by themselves establish a particular transcriptional mechanism in fission yeast.
Summary: This ARBA assertion is not independent experimental evidence.
Reason: This ARBA assertion is not independent experimental evidence. The target has PHD/RING domains and its curated ortholog is an RNA-polymerase-associated E3 ligase, but that alone does not establish this specific fission-yeast localization or assembly. The exact claim requires target localization or complex evidence.
ISO PMID:19064926 Modulation of RNA polymerase II subunit composition by ubiqu...
ACCEPT
Summary: PomBase assigns E3 ubiquitin-ligase activity by curated orthology to experimentally characterized budding-yeast Asr1.
Reason: PomBase assigns E3 ubiquitin-ligase activity by curated orthology to experimentally characterized budding-yeast Asr1. The target retains RING/PHD architecture, making the enzymatic transfer credible. The source directly demonstrates a RING ubiquitin ligase, but its Rpb1/Rpb2 substrate specificity and polymerase subunit-ejection mechanism remain ortholog evidence rather than observations on the fission-yeast target.
Here, we report that the Saccharomyces cerevisiae protein Asr1 is a RING finger ubiquitin-ligase that binds directly to RNA polymerase II via the carboxyl-terminal domain (CTD) of the largest subunit of the enzyme.
file:SCHPO/asr1/asr1-uniprot.txt
DR Pfam; PF00628; PHD; 1. DR Pfam; PF13639; zf-RING_2; 1.
Core Functions
RING-type ubiquitin ligase inferred from curated Asr1 orthology and conserved zinc-finger architecture; target substrates are unresolved.
Here, we report that the Saccharomyces cerevisiae protein Asr1 is a RING finger ubiquitin-ligase that binds directly to RNA polymerase II via the carboxyl-terminal domain (CTD) of the largest subunit of the enzyme.
file:SCHPO/asr1/asr1-uniprot.txt
DR Pfam; PF00628; PHD; 1. DR Pfam; PF13639; zf-RING_2; 1.
Q: Which endogenous proteins are ubiquitylated by Asr1 in fission yeast, and does the PHD finger specify chromatin recruitment?
External Prediction Reviews
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.
Review rationale: Metal ion binding is a credible consequence of the target zinc-finger architecture. The reviewed sequence record identifies a PHD finger at residues 122-170 through PROSITE-ProRule PRU00146 and an atypical RING region; the actual PHD sequence retains its cysteine/histidine-rich ligand pattern. This is a sequence/domain-based inference, with no direct target zinc-binding assay. Zinc and zinc-finger annotations already provide the more specific metal identity, and the XML itself records hydration from GO:0008270. The broad metal-ion prediction therefore recovers a known, less precise property rather than a novel function.