Gene Ontology annotation based on UniProtKB/Swiss-Prot keyword mapping
Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location vocabulary mapping, accompanied by conservative changes to GO terms applied by UniProt
Role of yeast SIR genes and mating type in directing DNA double-strand breaks to homologous and non-homologous repair paths.
Nej1p, a cell type-specific regulator of nonhomologous end joining in yeast.
Multiple interactions in Sir protein recruitment by Rap1p at silencers and telomeres in yeast.
NEJ1 controls non-homologous end joining in Saccharomyces cerevisiae.
Systematic identification of protein complexes in Saccharomyces cerevisiae by mass spectrometry.
Rap1-Sir4 binding independent of other Sir, yKu, or histone interactions initiates the assembly of telomeric heterochromatin in yeast.
Separation-of-function mutants of yeast Ku80 reveal a Yku80p-Sir4p interaction involved in telomeric silencing.
Budding yeast silencing complexes and regulation of Sir2 activity by protein-protein interactions.
Proteome survey reveals modularity of the yeast cell machinery.
Global landscape of protein complexes in the yeast Saccharomyces cerevisiae.
Domain structure and protein interactions of the silent information regulator Sir3 revealed by screening a nested deletion library of protein fragments.
Inhibition of homologous recombination by a cohesin-associated clamp complex recruited to the rDNA recombination enhancer.
A novel role for histone chaperones CAF-1 and Rtt106p in heterochromatin silencing.
Modifiers of position effect are shared between telomeric and silent mating-type loci in S. cerevisiae.
Reconstitution of yeast silent chromatin: multiple contact sites and O-AADPR binding load SIR complexes onto nucleosomes in vitro.
An atlas of chaperone-protein interactions in Saccharomyces cerevisiae: implications to protein folding pathways in the cell.
Defining the budding yeast chromatin-associated interactome.
Regulating repression: roles for the sir4 N-terminus in linker DNA protection and stabilization of epigenetic states.
A role for the nucleoporin Nup170p in chromatin structure and gene silencing.
Spatial reorganization of telomeres in long-lived quiescent cells.
Competition between Heterochromatic Loci Allows the Abundance of the Silencing Protein, Sir4, to Regulate de novo Assembly of Heterochromatin.
Quiescent Saccharomyces cerevisiae forms telomere hyperclusters at the nuclear membrane vicinity through a multifaceted mechanism involving Esc1, the Sir complex, and chromatin condensation.
Structural Insights into Yeast Telomerase Recruitment to Telomeres.
Four genes responsible for a position effect on expression from HML and HMR in Saccharomyces cerevisiae.
The social and structural architecture of the yeast protein interactome.
Silent information regulator protein complexes in Saccharomyces cerevisiae: a SIR2/SIR4 complex and evidence for a regulatory domain in SIR4 that inhibits its interaction with SIR3.
Components of the Ku-dependent non-homologous end-joining pathway are involved in telomeric length maintenance and telomeric silencing.
Sir proteins, Rif proteins, and Cdc13p bind Saccharomyces telomeres in vivo.
Yeast cell-type regulation of DNA repair.
Falcon deep research report on SIR4
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Sir4 is a non-enzymatic regulatory/scaffold protein whose primary
molecular function is to assemble and organize the multivalent
SIR silencing complex, bringing together the NAD+-dependent histone
deacetylase Sir2 and the nucleosome-binding structural factor Sir3,
and linking Sir2 catalytic activity to chromatin binding/spreading
mediated by Sir3.
"Sir4 is best understood as a **non-enzymatic regulatory/scaffold protein** whose primary molecular function is to **assemble and organize a multivalent silencing apparatus** by bringing together:"
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The Sir2-interaction domain (SID; residues 737-893) of Sir4 forms the
Sir2-Sir4 core scaffold; the interaction can allosterically stimulate
Sir2 activity and couple deacetylation to SIR spreading.
"Forms the Sir2–Sir4 core scaffold; recruits/allosterically supports Sir2 and couples deacetylation to SIR spreading"
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The Sir4 C-terminal coiled-coil (residues 1271-1347) mediates Sir4
homodimerization, generates two Sir3-binding sites, and also contacts
yKu70, linking Sir4 dimerization to Sir3 recruitment and telomere
tethering.
"Mediates Sir4 homodimerization, generates two Sir3-binding sites, supports effective silencing, and also contacts yKu70"
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The Sir4 partitioning and anchoring domain (PAD; residues 950-1262)
binds Esc1 and contains an H-BRCT-like module that recognizes
phosphorylated ligands, anchoring telomeric SIR domains to the inner
nuclear membrane/nuclear periphery and contributing to telomere
partitioning and clustering.
"Sir4 contains a PAD that binds Esc1 and includes an H-BRCT-like module that recognizes phosphorylated ligands (including Esc1), supporting perinuclear anchoring and repression"
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Quantitative buffering analysis identifies Sir4 as the limiting SIR
component for silencing robustness, more sensitive to dosage reduction
than Sir2 or Sir3, with telomeres competing with HM loci for a limiting
Sir4 pool during de novo heterochromatin assembly.
"Quantitative buffering analysis identifies Sir4 as the limiting SIR component for silencing robustness, more sensitive to dosage reduction than Sir2 or Sir3."
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At telomeres the SIR complex is recruited to TG1-3 repeats via Rap1,
with Sir4-Rap1 binding central to nucleation models; Rap1's C-terminus
binds Sir4 (and Sir3), providing a direct telomeric recruitment
mechanism.
"Rap1’s C-terminus binds Sir4 (and Sir3), providing a direct telomeric recruitment mechanism"