Pkn is a novel partner of cyclin T2a in muscle differentiation

J Cell Physiol. 2006 Apr;207(1):232-7. doi: 10.1002/jcp.20566.


With the aim to find novel partners of human Cyclin T2a, we performed a two-hybrid screening in yeast using the full-length cDNA of this cyclin as bait, and a human heart cDNA library as preys source. Upon several interesting genes selected, our attention has been focused on the cDNA coding for PKNalpha, a fatty acid- and Rho-activated serine/threonine protein kinase, having a catalytic domain homologous to protein kinase C family. Co-immunoprecipitation and in vitro pull-down assays independently confirmed the interaction between the two proteins. Luciferase assays, performed on NIH3T3 cell extracts after transfection with a MyoD-responsive promoter, pointed out that PKNalpha was able to enhance MyoD-dependent transcription, and that this effect was further increased when cyclin T2a was co-overexpressed. Finally, overexpression of both Cyclin T2a and PKNalpha in C2C12 cells strongly enhanced the expression of myogenic differentiation markers, such as Myogenin and Myosin Heavy Chain, during starvation-induced differentiation. Taken together, our data strengthen the hypothesis that Cyclin T2a plays a role in muscle differentiation, and propose PKNalpha as a novel partner of Cyclin T2a in this process.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Binding Sites / genetics
  • Binding, Competitive
  • Cell Differentiation*
  • Cell Line
  • Cyclin T
  • Cyclin-Dependent Kinase 9 / genetics
  • Cyclin-Dependent Kinase 9 / metabolism
  • Cyclins / genetics
  • Cyclins / metabolism*
  • DNA, Complementary / genetics
  • Gene Expression / genetics
  • Humans
  • Mice
  • Muscle Cells / cytology
  • Muscle Cells / metabolism*
  • Mutation
  • MyoD Protein / genetics
  • MyoD Protein / metabolism
  • Myogenin / metabolism
  • Myosin Heavy Chains / metabolism
  • NIH 3T3 Cells
  • Plasmids / genetics
  • Protein Binding
  • Protein Kinase C
  • Protein Serine-Threonine Kinases / genetics
  • Protein Serine-Threonine Kinases / metabolism*
  • Protein-Tyrosine Kinases / genetics
  • Protein-Tyrosine Kinases / metabolism*
  • Recombinant Proteins / metabolism
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism
  • Transfection
  • Two-Hybrid System Techniques


  • CCNT2 protein, human
  • Cyclin T
  • Cyclins
  • DNA, Complementary
  • MyoD Protein
  • Myogenin
  • Recombinant Proteins
  • protein kinase N
  • Protein-Tyrosine Kinases
  • Protein Serine-Threonine Kinases
  • Protein Kinase C
  • CDK9 protein, human
  • Cyclin-Dependent Kinase 9
  • Myosin Heavy Chains