cyclin H (MO15-associated protein, CCNH)

Function

• cyclin component of CDK-activating kinase
• regulates CDK7, the catalytic subunit of the CDK-activating kinase (CAK) enzymatic complex
• CAK activates the cyclin-associated kinases CDC2/CDK1, CDK2, CDK4 & CDK6 by threonine phosphorylation
• CAK complexed to the core-TFIIH basal transcription factor activates RNA polymerase 2 by serine 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
• expression & activity are constant throughout the cell cycle
• associates primarily with CDK7 & MAT1 to form the CAK complex
• CAK can further associate with the core-TFIIH to form the TFIIH basal transcription factor

Structure

belongs to the cyclin family. cyclin C subfamily

Compartment

nucleus

More general terms

• cyclin
• phosphoprotein

Component of

• CDK7/cyclin H complex, CDK-activating kinase (CAK) or p34cdc2 activating kinase

Database

• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:902
• OMIM: https://mirror.omim.org/entry/601953
• UniProt: http://www.uniprot.org/uniprot/P51946.html
• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=902