CDK9 keeps RNA polymerase II on track

Cell Mol Life Sci. 2021 Jul;78(14):5543-5567. doi: 10.1007/s00018-021-03878-8. Epub 2021 Jun 19.


Cyclin-dependent kinase 9 (CDK9), the kinase component of positive transcription elongation factor b (P-TEFb), is essential for transcription of most protein-coding genes by RNA polymerase II (RNAPII). By releasing promoter-proximally paused RNAPII into gene bodies, CDK9 controls the entry of RNAPII into productive elongation and is, therefore, critical for efficient synthesis of full-length messenger (m)RNAs. In recent years, new players involved in P-TEFb-dependent processes have been identified and an important function of CDK9 in coordinating elongation with transcription initiation and termination has been unveiled. As the regulatory functions of CDK9 in gene expression continue to expand, a number of human pathologies, including cancers, have been associated with aberrant CDK9 activity, underscoring the need to properly regulate CDK9. Here, I provide an overview of CDK9 function and regulation, with an emphasis on CDK9 dysregulation in human diseases.

Keywords: 7SK RNA; Cyclin T1; HIV; Promoter-proximal pausing; RNA polymerase II CTD; Transcriptional checkpoint.

Publication types

  • Review

MeSH terms

  • Animals
  • Cyclin-Dependent Kinase 9 / genetics
  • Cyclin-Dependent Kinase 9 / metabolism*
  • Cyclin-Dependent Kinases / genetics
  • Cyclin-Dependent Kinases / metabolism*
  • Humans
  • Phosphorylation
  • RNA Polymerase II / genetics
  • RNA Polymerase II / metabolism*
  • Transcription, Genetic*


  • Cyclin-Dependent Kinase 9
  • Cyclin-Dependent Kinases
  • RNA Polymerase II