Cyclin-dependent kinase 12 increases 3' end processing of growth factor-induced c-FOS transcripts

Mol Cell Biol. 2015 Jan;35(2):468-78. doi: 10.1128/MCB.01157-14. Epub 2014 Nov 10.


Transcriptional cyclin-dependent kinases (CDKs) regulate RNA polymerase II initiation and elongation as well as cotranscriptional mRNA processing. In this report, we describe an important role for CDK12 in the epidermal growth factor (EGF)-induced c-FOS proto-oncogene expression in mammalian cells. This kinase was found in the exon junction complexes (EJC) together with SR proteins and was thus recruited to RNA polymerase II. In cells depleted of CDK12 or eukaryotic translation initiation factor 4A3 (eIF4A3) from the EJC, EGF induced fewer c-FOS transcripts. In these cells, phosphorylation of serines at position 2 in the C-terminal domain (CTD) of RNA polymerase II, as well as levels of cleavage-stimulating factor 64 (Cstf64) and 73-kDa subunit of cleavage and polyadenylation specificity factor (CPSF73), was reduced at the c-FOS gene. These effects impaired 3' end processing of c-FOS transcripts. Mutant CDK12 proteins lacking their Arg-Ser-rich (RS) domain or just the RS domain alone acted as dominant negative proteins. Thus, CDK12 plays an important role in cotranscriptional processing of c-FOS transcripts.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cyclin-Dependent Kinases / genetics
  • Cyclin-Dependent Kinases / metabolism*
  • Humans
  • Intercellular Signaling Peptides and Proteins / metabolism*
  • Mutation / genetics*
  • Phosphorylation
  • Proto-Oncogene Mas
  • Proto-Oncogene Proteins c-fos / genetics
  • Proto-Oncogene Proteins c-fos / metabolism*
  • RNA Polymerase II / metabolism*
  • RNA, Messenger / genetics*
  • Transcriptional Activation / genetics


  • Intercellular Signaling Peptides and Proteins
  • MAS1 protein, human
  • Proto-Oncogene Mas
  • Proto-Oncogene Proteins c-fos
  • RNA, Messenger
  • CDK12 protein, human
  • Cyclin-Dependent Kinases
  • RNA Polymerase II