Alternative mechanisms of CAK assembly require an assembly factor or an activating kinase

Cell. 1995 Oct 6;83(1):47-57. doi: 10.1016/0092-8674(95)90233-3.


We have cloned a mouse cDNA that encodes p36, a novel subunit of the CDK-activating kinase (CAK). p36 contains a C3HC4 zinc-binding domain or RING factor and is associated both with a TFIIH-bound form of CAK and with a free trimeric form. p36 promotes the assembly of CDK7 and cyclin H in vitro, stabilizing the transient CDK7-cyclin H complex. Stabilization and activation of CAK by p36 is independent of the phosphorylation state of T170, the conserved activating residue of CDK7. Assembly of active CDK7-cyclin H dimers can also occur through an alternative p36-independent pathway that requires phosphorylation of T170 by a CAK-activating kinase, or CAKAK. Thus, CDK7-cyclin H complex formation can be achieved by multiple mechanisms.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Cyclin H
  • Cyclin-Dependent Kinases*
  • Cyclins / metabolism*
  • DNA, Complementary / genetics*
  • Feedback
  • Mice
  • Molecular Sequence Data
  • Protein Conformation
  • Protein-Serine-Threonine Kinases / metabolism*
  • Sequence Alignment


  • Ccnh protein, mouse
  • Cyclin H
  • Cyclins
  • DNA, Complementary
  • Protein-Serine-Threonine Kinases
  • Cyclin-Dependent Kinases
  • cyclin-dependent kinase-activating kinase

Associated data

  • GENBANK/U35249