UniProt functional annotation for Q9UIF9



	UniProt functional annotation for Q9UIF9

UniProt code: Q9UIF9.

Organism: Homo sapiens (Human).

Taxonomy: Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae; Homo.

Function: Essential component of the NoRC (nucleolar remodeling complex) complex, a complex that mediates silencing of a fraction of rDNA by recruiting histone-modifying enzymes and DNA methyltransferases, leading to heterochromatin formation and transcriptional silencing. In the complex, it plays a central role by being recruited to rDNA and by targeting chromatin modifying enzymes such as HDAC1, leading to repress RNA polymerase I transcription. Recruited to rDNA via its interaction with TTF1 and its ability to recognize and bind histone H4 acetylated on 'Lys-16' (H4K16ac), leading to deacetylation of H4K5ac, H4K8ac, H4K12ac but not H4K16ac. Specifically binds pRNAs, 150-250 nucleotide RNAs that are complementary in sequence to the rDNA promoter; pRNA-binding is required for heterochromatin formation and rDNA silencing (By similarity). {ECO:0000250}.

Subunit: Component of the NoRC complex, at least composed of SMARCA5/SNF2H and BAZ2A/TIP5. Interacts with TTF1; required for recruitment of the NoRC complex to rDNA. Interacts with DNMT1, DNM3B, HDAC1 and SIN3A (By similarity). Interacts with BEND3 and USP21. {ECO:0000250|UniProtKB:Q91YE5, ECO:0000269|PubMed:26100909}.

Subcellular location: Nucleus, nucleolus {ECO:0000250}. Note=Colocalizes with the basal RNA polymerase I transcription factor UBF in the nucleolus. {ECO:0000250}.

Tissue specificity: Expressed at moderate levels in most tissues analyzed, including heart, brain, placenta, lung, skeletal muscle, kidney and pancreas.

Domain: The bromo domain and the PHD-type zinc finger recognize and bind histone H4 acetylated on 'Lys-16' (H4K16ac). These 2 domains play a central role in the recruitment of chromatin silencing proteins such as DNMT1, DNMT3B and HDAC1.

Domain: The MBD (methyl-CpG-binding) domain, also named TAM domain, specifically recognizes and binds a conserved stem-loop structure the association within pRNA. Binding to pRNA induces a conformational change of BAZ2A/TIP5 and is essential for targeting the NoRC complex to the nucleolus (By similarity). {ECO:0000250}.

Ptm: Acetylation at Lys-680 by KAT8/MOF promotes its dissociation from pRNA, affecting heterochromatin formation, nucleosome positioning and rDNA silencing. Deacetylation by SIRT1 in late S phase enhances pRNA- binding, allowing de novo DNA methylation and heterochromatin formation. Acetylation is high during S phase and declines to background levels in late S phase when the silent copies of rRNA genes are replicated (By similarity). {ECO:0000250}.

Ptm: Ubiquitinated. Deubiquitinated by USP21 leading to its stabilization. {ECO:0000269|PubMed:26100909}.

Similarity: Belongs to the WAL family. {ECO:0000305}.

Sequence caution: Sequence=AAB60864.1; Type=Miscellaneous discrepancy; Note=Contaminating sequence. Potential poly-A sequence.; Evidence={ECO:0000305}; Sequence=BAG51228.1; Type=Erroneous termination; Note=Truncated C-terminus.; Evidence={ECO:0000305};

Annotations taken from UniProtKB at the EBI.


Organism:		Homo sapiens (Human).
Taxonomy:		Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae; Homo.



Function:		Essential component of the NoRC (nucleolar remodeling complex) complex, a complex that mediates silencing of a fraction of rDNA by recruiting histone-modifying enzymes and DNA methyltransferases, leading to heterochromatin formation and transcriptional silencing. In the complex, it plays a central role by being recruited to rDNA and by targeting chromatin modifying enzymes such as HDAC1, leading to repress RNA polymerase I transcription. Recruited to rDNA via its interaction with TTF1 and its ability to recognize and bind histone H4 acetylated on 'Lys-16' (H4K16ac), leading to deacetylation of H4K5ac, H4K8ac, H4K12ac but not H4K16ac. Specifically binds pRNAs, 150-250 nucleotide RNAs that are complementary in sequence to the rDNA promoter; pRNA-binding is required for heterochromatin formation and rDNA silencing (By similarity). {ECO:0000250}.


Subunit:		Component of the NoRC complex, at least composed of SMARCA5/SNF2H and BAZ2A/TIP5. Interacts with TTF1; required for recruitment of the NoRC complex to rDNA. Interacts with DNMT1, DNM3B, HDAC1 and SIN3A (By similarity). Interacts with BEND3 and USP21. {ECO:0000250\|UniProtKB:Q91YE5, ECO:0000269\|PubMed:26100909}.
Subcellular location:		Nucleus, nucleolus {ECO:0000250}. Note=Colocalizes with the basal RNA polymerase I transcription factor UBF in the nucleolus. {ECO:0000250}.
Tissue specificity:		Expressed at moderate levels in most tissues analyzed, including heart, brain, placenta, lung, skeletal muscle, kidney and pancreas.
Domain:		The bromo domain and the PHD-type zinc finger recognize and bind histone H4 acetylated on 'Lys-16' (H4K16ac). These 2 domains play a central role in the recruitment of chromatin silencing proteins such as DNMT1, DNMT3B and HDAC1.
Domain:		The MBD (methyl-CpG-binding) domain, also named TAM domain, specifically recognizes and binds a conserved stem-loop structure the association within pRNA. Binding to pRNA induces a conformational change of BAZ2A/TIP5 and is essential for targeting the NoRC complex to the nucleolus (By similarity). {ECO:0000250}.
Ptm:		Acetylation at Lys-680 by KAT8/MOF promotes its dissociation from pRNA, affecting heterochromatin formation, nucleosome positioning and rDNA silencing. Deacetylation by SIRT1 in late S phase enhances pRNA- binding, allowing de novo DNA methylation and heterochromatin formation. Acetylation is high during S phase and declines to background levels in late S phase when the silent copies of rRNA genes are replicated (By similarity). {ECO:0000250}.
Ptm:		Ubiquitinated. Deubiquitinated by USP21 leading to its stabilization. {ECO:0000269\|PubMed:26100909}.
Similarity:		Belongs to the WAL family. {ECO:0000305}.
Sequence caution:		Sequence=AAB60864.1; Type=Miscellaneous discrepancy; Note=Contaminating sequence. Potential poly-A sequence.; Evidence={ECO:0000305}; Sequence=BAG51228.1; Type=Erroneous termination; Note=Truncated C-terminus.; Evidence={ECO:0000305};