CDK-activating kinase assembly factor MAT1; RING finger protein MAT1; menage a trois; CDK7/cyclin-H assembly factor; p36; p35; cyclin-G1-interacting protein; RING finger protein 66 (MNAT1, CAP35, MAT1, RNF66)

Function

• stabilizes cyclin H-CDK7 complex to form a functional CDK-activating kinase (CAK) enzymatic complex
• CAK activates the cyclin-associated kinases CDC2/CDK1, CDK2, CDK4 & CDK6 by Thr phosphorylation
• CAK complexed to the core-TFIIH basal transcription factor activates RNA polymerase 2 by Ser phosphorylation of the repetitive C-terminus domain (CTD) of its large subunit (POLR2A), allowing its escape from the promoter & elongation of the transcripts
• involved in cell cycle control & in RNA transcription by RNA polymerase 2
• associates primarily with CDK7 & cyclin H to form the CAK complex
• CAK can further associate with the core-TFIIH to form the TFIIH basal transcription factor

Structure

• contains 1 RING-type Zn+2 finger
• contains 1 UIM (ubiquitin-interacting motif) repeat

Compartment

• nucleus

Expression

• highest levels in colon & testis
• moderate levels are present thymus, prostate, ovary, & small intestine
• lowest levels are found in spleen & leukocytes

More general terms

• ring finger protein
• nuclear protein
• phosphoprotein

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=4331
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:4331
• OMIM: https://mirror.omim.org/entry/602659
• UniProt: http://www.uniprot.org/uniprot/P51948.html