Cyclin-dependent kinase 9

Cyclin-dependent kinase 9

Protein kinase involved in the regulation of transcription10574912,10757782,11145967,11575923,11809800,11884399,14701750,16109376,16109377,20930849,28426094,29335245. 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 RDBP10574912,10757782,11145967,11575923,11809800,11884399,14701750,16109376,16109377,16427012,20930849,28426094,30134174. This complex is inactive when in the 7SK snRNP complex form10574912,10757782,11145967,11575923,11809800,11884399,14701750,16109376,16109377,20930849,28426094. Phosphorylates EP300, MYOD1, RPB1/POLR2A and AR and the negative elongation factors DSIF and NELFE10912001,11112772,12037670,16427012,20081228,20980437,21127351,9857195. 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)17956865,18362169. Promotes RNA synthesis in genetic programs for cell growth, differentiation and viral pathogenesis10393184,11112772. P-TEFb is also involved in cotranscriptional histone modification, mRNA processing and mRNA export15564463,19575011,19844166,28539972. 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 processing15564463,19575011,19844166. Also catalyzes phosphorylation of histone H1.4 (H1-4) at Ser-187' (H1.4S187Ph), a modification associated with transcription activation28539972. 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 vitro21127351. 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 damage20493174. In addition, probable function in DNA repair of isoform 2 via interaction with KU70/XRCC620493174. Promotes cardiac myocyte enlargement20081228. RPB1/POLR2A phosphorylation on 'Ser-2' in CTD activates transcription21127351. AR phosphorylation modulates AR transcription factor promoter selectivity and cell growth. DSIF and NELF phosphorylation promotes transcription by inhibiting their negative effect10912001,11112772,9857195. The phosphorylation of MYOD1 enhances its transcriptional activity and thus promotes muscle differentiation12037670. Catalyzes phosphorylation of KAT5, promoting KAT5 recruitment to chromatin and histone acetyltransferase activity29335245

Quoted from UniProt’s FUNCTION annotation for P50750 (reviewed). The superscript numbers are UniProt’s own PubMed citations, kept in the sentence and in order, each linking to the paper it names.

What it acts with

STRING’s highest-confidence human functional partners. The combined score mixes several kinds of evidence, so each channel is shown separately — a partner supported by experiment is a different claim from one supported only by text mining, and for a receptor this is where its coupling appears as evidence rather than as assertion.

Where it sits in the cell

• Nucleoplasm
• Cytoplasmic bodiesadditional

Human Protein Atlas, by antibody immunofluorescence in cell lines — a different assay from the expression figures below, which are RNA.

UniProt, curated Nucleus · Cytoplasm · Nucleus, PML body