UniProt functional annotation for Q15020



	UniProt functional annotation for Q15020

UniProt code: Q15020.

Organism: Homo sapiens (Human).

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

Function: U6 snRNP-binding protein that functions as a recycling factor of the splicing machinery. Promotes the initial reassembly of U4 and U6 snRNPs following their ejection from the spliceosome during its maturation (PubMed:12032085). Also binds U6atac snRNPs and may function as a recycling factor for U4atac/U6atac spliceosomal snRNP, an initial step in the assembly of U12-type spliceosomal complex. The U12-type spliceosomal complex plays a role in the splicing of introns with non- canonical splice sites (PubMed:14749385). May also function as a substrate-targeting factor for deubiquitinases like USP4 and USP15. Recruits USP4 to ubiquitinated PRPF3 within the U4/U5/U6 tri-snRNP complex, promoting PRPF3 deubiquitination and thereby regulating the spliceosome U4/U5/U6 tri-snRNP spliceosomal complex disassembly (PubMed:20595234). May also recruit the deubiquitinase USP15 to histone H2B and mediate histone deubiquitination, thereby regulating gene expression and/or DNA repair (PubMed:24526689). May play a role in hematopoiesis probably through transcription regulation of specific genes including MYC (By similarity). {ECO:0000250|UniProtKB:Q9JLI8, ECO:0000269|PubMed:12032085, ECO:0000269|PubMed:14749385, ECO:0000269|PubMed:20595234, ECO:0000269|PubMed:24526689}.

Function: Regulates Tat transactivation activity through direct interaction. May be a cellular factor for HIV-1 gene expression and viral replication. {ECO:0000269|PubMed:11959860}.

Subunit: Component of the 7SK snRNP complex at least composed of P-TEFb (composed of CDK9 and CCNT1/cyclin-T1), HEXIM1, HEXIM2, BCDIN3, SART3 proteins and 7SK and U6 snRNAs (PubMed:17643375). Interacts with AGO1 and AGO2 (PubMed:17932509). Interacts with PRPF3 and USP4; the interaction with PRPF3 is direct and recruits USP4 to its substrate PRPF3 (PubMed:15314151, PubMed:20595234). Interacts with USP15; the interaction is direct (PubMed:24526689). Interacts with HIV-1 Tat (PubMed:11959860). {ECO:0000269|PubMed:11959860, ECO:0000269|PubMed:15314151, ECO:0000269|PubMed:17643375, ECO:0000269|PubMed:17932509, ECO:0000269|PubMed:20595234, ECO:0000269|PubMed:24526689}.

Subcellular location: Nucleus, nucleoplasm {ECO:0000269|PubMed:10463607, ECO:0000269|PubMed:11959860, ECO:0000269|PubMed:12578909}. Nucleus, Cajal body {ECO:0000269|PubMed:12578909}. Nucleus speckle {ECO:0000269|PubMed:11959860}. Cytoplasm {ECO:0000269|PubMed:10463607, ECO:0000269|PubMed:11959860}.

Tissue specificity: Ubiquitously expressed. {ECO:0000269|PubMed:11959860}.

Miscellaneous: [Isoform 2]: May be produced at very low levels due to a premature stop codon in the mRNA, leading to nonsense-mediated mRNA decay. Inactive in U4/U6 snRNP recycling. {ECO:0000269|PubMed:15314151}.

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:		U6 snRNP-binding protein that functions as a recycling factor of the splicing machinery. Promotes the initial reassembly of U4 and U6 snRNPs following their ejection from the spliceosome during its maturation (PubMed:12032085). Also binds U6atac snRNPs and may function as a recycling factor for U4atac/U6atac spliceosomal snRNP, an initial step in the assembly of U12-type spliceosomal complex. The U12-type spliceosomal complex plays a role in the splicing of introns with non- canonical splice sites (PubMed:14749385). May also function as a substrate-targeting factor for deubiquitinases like USP4 and USP15. Recruits USP4 to ubiquitinated PRPF3 within the U4/U5/U6 tri-snRNP complex, promoting PRPF3 deubiquitination and thereby regulating the spliceosome U4/U5/U6 tri-snRNP spliceosomal complex disassembly (PubMed:20595234). May also recruit the deubiquitinase USP15 to histone H2B and mediate histone deubiquitination, thereby regulating gene expression and/or DNA repair (PubMed:24526689). May play a role in hematopoiesis probably through transcription regulation of specific genes including MYC (By similarity). {ECO:0000250\|UniProtKB:Q9JLI8, ECO:0000269\|PubMed:12032085, ECO:0000269\|PubMed:14749385, ECO:0000269\|PubMed:20595234, ECO:0000269\|PubMed:24526689}.



Function:		Regulates Tat transactivation activity through direct interaction. May be a cellular factor for HIV-1 gene expression and viral replication. {ECO:0000269\|PubMed:11959860}.


Subunit:		Component of the 7SK snRNP complex at least composed of P-TEFb (composed of CDK9 and CCNT1/cyclin-T1), HEXIM1, HEXIM2, BCDIN3, SART3 proteins and 7SK and U6 snRNAs (PubMed:17643375). Interacts with AGO1 and AGO2 (PubMed:17932509). Interacts with PRPF3 and USP4; the interaction with PRPF3 is direct and recruits USP4 to its substrate PRPF3 (PubMed:15314151, PubMed:20595234). Interacts with USP15; the interaction is direct (PubMed:24526689). Interacts with HIV-1 Tat (PubMed:11959860). {ECO:0000269\|PubMed:11959860, ECO:0000269\|PubMed:15314151, ECO:0000269\|PubMed:17643375, ECO:0000269\|PubMed:17932509, ECO:0000269\|PubMed:20595234, ECO:0000269\|PubMed:24526689}.
Subcellular location:		Nucleus, nucleoplasm {ECO:0000269\|PubMed:10463607, ECO:0000269\|PubMed:11959860, ECO:0000269\|PubMed:12578909}. Nucleus, Cajal body {ECO:0000269\|PubMed:12578909}. Nucleus speckle {ECO:0000269\|PubMed:11959860}. Cytoplasm {ECO:0000269\|PubMed:10463607, ECO:0000269\|PubMed:11959860}.
Tissue specificity:		Ubiquitously expressed. {ECO:0000269\|PubMed:11959860}.
Miscellaneous:		[Isoform 2]: May be produced at very low levels due to a premature stop codon in the mRNA, leading to nonsense-mediated mRNA decay. Inactive in U4/U6 snRNP recycling. {ECO:0000269\|PubMed:15314151}.