Cdk9
entrez
362110
canonical
uniprot
Q641Z4
canonical
genesymbol
Cdk9
resolver
uniprot_entry
CDK9_RAT
resolver
activity_regulation
ACTIVITY REGULATION: Activation by Thr-186 phosphorylation is calcium Ca(2+) signaling pathway-dependent; actively inactivated by dephosphorylation mediated by PPP1CA, PPM1A and PPM1B. Reversibly repressed by acetylation at Lys-44 and Lys-48 (By similarity). {ECO:0000250|UniProtKB:P50750}.
uniprot
proteins
amino_acid_sequence
MAKQYDSVECPFCDEVTKYEKLAKIGQGTFGEVFKAKHRQTGQKVALKKVLMENEKEGFPITALREIKILQLLKHENVVNLIEICRTKASPYNRCKGSIYLVFDFCEHDLAGLLSNVLVKFTLSEIKRVMQMLLNGLYYIHRNKILHRDMKAANVLITRDGVLKLADFGLARAFSLAKNSQPNRYTNRVVTLWYRPPELLLGERDYGPPIDLWGAGCIMAEMWTRSPIMQGNTEQHQLALISQLCGSITPEVWPNVDKYELFEKLELVKGQKRKVKDRLKAYVRDPYALDLIDKLLVLDPAQRIDSDDALNHDFFWSDPMPSDLKGMLSTHLTSMFEYLAPPRRKGSQITQQSTNQSRNPATTNQTEFERVF
uniprot
proteins
ec_number
2.7.11.22
uniprot
proteins
ec_number
2.7.11.23
uniprot
proteins
function
FUNCTION: Protein kinase involved in the regulation of transcription. Member of the cyclin-dependent kinase pair (CDK9/cyclin-T) complex, also called positive transcription elongation factor b (P-TEFb), which facilitates the transition from abortive to productive elongation by phosphorylating the CTD (C-terminal domain) of the large subunit of RNA polymerase II (RNAP II) POLR2A, SUPT5H and RDBP. This complex is inactive when in the 7SK snRNP complex form. Phosphorylates EP300, MYOD1, RPB1/POLR2A and AR and the negative elongation factors DSIF and NELFE. Regulates cytokine inducible transcription networks by facilitating promoter recognition of target transcription factors (e.g. TNF-inducible RELA/p65 activation and IL-6-inducible STAT3 signaling). Promotes RNA synthesis in genetic programs for cell growth, differentiation and viral pathogenesis. P-TEFb is also involved in cotranscriptional histone modification, mRNA processing and mRNA export. Modulates a complex network of chromatin modifications including histone H2B monoubiquitination (H2Bub1), H3 lysine 4 trimethylation (H3K4me3) and H3K36me3; integrates phosphorylation during transcription with chromatin modifications to control co-transcriptional histone mRNA processing. Also catalyzes phosphorylation of histone H1.4 (H1-4) at 'Ser-187' (H1.4S187Ph), a modification associated with transcription activation. The CDK9/cyclin-K complex has also a kinase activity towards CTD of RNAP II and can substitute for CDK9/cyclin-T P-TEFb in vitro. Replication stress response protein; the CDK9/cyclin-K complex is required for genome integrity maintenance, by promoting cell cycle recovery from replication arrest and limiting single-stranded DNA amount in response to replication stress, thus reducing the breakdown of stalled replication forks and avoiding DNA damage. In addition, probable function in DNA repair of isoform 2 via interaction with KU70/XRCC6. Promotes cardiac myocyte enlargement. RPB1/POLR2A phosphorylation on 'Ser-2' in CTD activates transcription. AR phosphorylation modulates AR transcription factor promoter selectivity and cell growth. DSIF and NELF phosphorylation promotes transcription by inhibiting their negative effect. The phosphorylation of MYOD1 enhances its transcriptional activity and thus promotes muscle differentiation. Catalyzes phosphorylation of KAT5, promoting KAT5 recruitment to chromatin and histone acetyltransferase activity. {ECO:0000250|UniProtKB:P50750}.
uniprot
proteins
mass_dalton
42762
uniprot
proteins
post_translational_modification
PTM: Autophosphorylation at Thr-186, Ser-347, Thr-350, Ser-353, Thr-354 and Ser-357 triggers kinase activity by promoting cyclin and substrate binding upon conformational changes. Thr-186 phosphorylation requires the calcium Ca(2+) signaling pathway, including CaMK1D and calmodulin. This inhibition is relieved by Thr-29 dephosphorylation. Phosphorylation at Ser-175 inhibits kinase activity. Can be phosphorylated on either Thr-362 or Thr-363 but not on both simultaneously (By similarity). {ECO:0000250|UniProtKB:P50750}.; PTM: Dephosphorylation of Thr-186 by PPM1A and PPM1B blocks CDK9 activity and may lead to CDK9 proteasomal degradation. However, PPP1CA-mediated Thr-186 dephosphorylation is required to release P-TEFb from its inactive P-TEFb/7SK snRNP complex. Dephosphorylated at Ser-347 by the PNUTS-PP1 complex during RNA polymerase II transcription pause-release. Dephosphorylation of C-terminus Thr and Ser residues by protein phosphatase-1 (PP1) triggers CDK9 activity. {ECO:0000250|UniProtKB:P50750}.; PTM: N6-acetylation of Lys-44 promotes kinase activity, whereas acetylation of both Lys-44 and Lys-48 mediated by PCAF/KAT2B and GCN5/KAT2A reduces kinase activity. The acetylated form associates with PML bodies in the nuclear matrix and with the transcriptionally silent HIV-1 genome; deacetylated upon transcription stimulation. Deacetylated by SIRT7, promoting the kinase activity and subsequent 'Ser-2' phosphorylation of the C-terminal domain (CTD) of RNA polymerase II. {ECO:0000250|UniProtKB:P50750}.; PTM: Polyubiquitinated and thus activated by UBR5. This ubiquitination is promoted by TFIIS/TCEA1 and favors 'Ser-2' phosphorylation of RPB1/POLR2A CTD (By similarity). {ECO:0000250|UniProtKB:P50750}.
uniprot
proteins
protein_family
CDC2/CDKX subfamily
uniprot
proteins
protein_family
CMGC Ser/Thr protein kinase family
uniprot
proteins
protein_family
Protein kinase superfamily
uniprot
proteins
pubmed
15489334
uniprot
proteins
sequence_length
372
uniprot
proteins
subcellular_location
SUBCELLULAR LOCATION: Nucleus {ECO:0000250}. Cytoplasm {ECO:0000250}. Nucleus, PML body {ECO:0000250}. Note=Accumulates on chromatin in response to replication stress. Complexed with CCNT1 in nuclear speckles, but uncomplexed form in the cytoplasm. The translocation from nucleus to cytoplasm is XPO1/CRM1-dependent. Associates with PML body when acetylated (By similarity). {ECO:0000250}.
uniprot
proteins