241 human active and 13 inactive phosphatases in total;
194 phosphatases have substrate data;
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336 protein substrates;
83 non-protein substrates;
1215 dephosphorylation interactions;
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299 KEGG pathways;
876 Reactome pathways;
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last scientific update: 11 Mar, 2019
last maintenance update: 01 Sep, 2023
Protein phosphatase that catalyzes the dephosphorylationof the C-terminal domain of RNA polymerase II Plays a role in RNAprocessing and termination Plays a role in pre-mRNApolyadenylation via its interaction with SYMPK
The mRNA surveillance pathway is a quality control mechanism that detects and degrades abnormal mRNAs. These pathways include nonsense-mediated mRNA decay (NMD), nonstop mRNA decay (NSD), and no-go decay (NGD). NMD is a mechanism that eliminates mRNAs containing premature translation-termination codons (PTCs). In vertebrates, PTCs trigger efficient NMD when located upstream of an exon junction complex (EJC). Upf3, together with Upf1 and Upf2, may signal the presence of the PTC to the 5'end of the transcript, resulting in decapping and rapid exonucleolytic digestion of the mRNA. In the NSD pathway, which targets mRNAs lacking termination codons, the ribosome is believed to translate through the 3' untranslated region and stall at the end of the poly(A) tail. NSD involves an eRF3-like protein, Ski7p, which is hypothesized to bind the empty A site of the ribosome and recruit the exosome to degrade the mRNA from the 3' end. NGD targets mRNAs with stalls in translation elongation for endonucleolytic cleavage in a process involving the Dom34 and Hbs1 proteins.
Small nuclear RNAs (snRNAs) play key roles in splicing and some of them, specifically the U1 and U2 snRNAs, are encoded by multicopy snRNA gene clusters containing tandem arrays of genes, about 30 in the RNU1 cluster (Bernstein et al. 1985) and about 10-20 in the RNU2 cluster (Van Ardsell and Weiner 1984). Whereas U6 snRNA genes are transcribed by RNA polymerase III, U1,U2, U4, U4atac, U5, U11, and U12 genes are transcribed by RNA polymerase II. Transcription of the U1 and U2 genes has been most extensively studied and the other snRNA genes as well as other genes with similar promoter structures, for example the SNORD13 gene, are inferred to be transcribed by similar reactions. The snRNA genes transcribed by RNA polymerase II are distinguished from mRNA-encoding genes by the presence of a proximal sequence element (PSE) rather than a TATA box and the presence of the Integrator complex rather than the Mediator complex (reviewed in Egloff et al. 2008, Jawdeker and Henry 2008).The snRNA genes are among the most rapidly transcribed genes in the genome. The 5' transcribed region of the U2 snRNA gene is largely single-stranded during interphase and metaphase (Pavelitz et al. 2008) and chromatin within the transcribed region is cleared of nucleosomes (O'Reilly et al. 2014). Transcriptional activation of the RNA polymerase II transcribed snRNA genes begins with binding of transcription factors to the distal sequence element (DSE) of the promoter (reviewed in Hernandez 2001, Egloff et al. 2008, Jawdeker and Henry 2008). The factors, which include POU2F1 (Oct-1), POU2F2 (Oct-2), ZNF143 (Staf) and Sp1, promote binding of the SNAPc complex (also known as PTF and PBP) to the PSE. SNAPc helps clear the gene of nucleosomes (O'Reilly et al. 2014) and recruits initiation factors (TFIIA, TFIIB, TFIIE, TFIIF, and snTAFc:TBP) which recruit RNA polymerase II. Phosphorylation of the C-terminal domain (CTD) of RNA polymerase II (reviewed in Egloff and Murphy 2008) by CDK7 recruits RPAP2 and the Integrator complex, which is required for later processing of the 3' end of the pre-snRNA transcript (reviewed in Chen and Wagner 2010, Baillat and Wagner 2015). The Little Elongation Complex (LEC) also appears to bind around the time of transcription initiation (Hu et al. 2013). As transcription proceeds, RPAP2 dephosphorylates serine-5 and P-TEFb phosphorylates serine-2 of the CTD. As transcription reaches the end of the snRNA gene serine-7 of the CTD is phosphorylated. These marks serve to bind protein complexes and are required for 3' processing of the pre-snRNA (reviewed in Egloff and Murphy 2008). After transcription proceeds through the conserved 3' processing sequence of the pre-snRNA the Integrator complex cleaves the pre-snRNA. Transcription then terminates downstream in a less well characterized reaction that requires elements of the polyadenylation system
Affinity Capture-Western, Reconstituted Complex, anti bait coimmunoprecipitation, anti tag coimmunoprecipitation, fluorescence microscopy, pull down, two hybrid
association, colocalization, direct interaction, physical, physical association
Affinity Capture-Western, Reconstituted Complex, anti bait coimmunoprecipitation, anti tag coimmunoprecipitation, fluorescence microscopy, pull down, two hybrid
association, colocalization, direct interaction, physical, physical association
Affinity Capture-Western, Reconstituted Complex, anti bait coimmunoprecipitation, anti tag coimmunoprecipitation, fluorescence microscopy, pull down, two hybrid
association, colocalization, direct interaction, physical, physical association
Affinity Capture-Western, Reconstituted Complex, anti bait coimmunoprecipitation, anti tag coimmunoprecipitation, fluorescence microscopy, pull down, two hybrid
association, colocalization, direct interaction, physical, physical association
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