Pkn is a novel partner of cyclin T2a in muscle differentiation.
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.
Cottone
Giuliano
G
Department for the Development of Therapeutic Programs, Center for Experimental Research, Regina Elena Cancer Institute, Rome, Italy.
Baldi
Alfonso
A
Palescandolo
Emanuele
E
Manente
Lucrezia
L
Penta
Roberta
R
Paggi
Marco G
MG
De Luca
Antonio
A
D000818:Animals; D001665:Binding Sites / Q000235:genetics; D001667:Binding, Competitive; D002454:Cell Differentiation; D002460:Cell Line; D056906:Cyclin T; D042863:Cyclin-Dependent Kinase 9 / Q000235:genetics / Q000378:metabolism; D016213:Cyclins / Q000235:genetics / Q000378:metabolism*; D018076:DNA, Complementary / Q000235:genetics; D015870:Gene Expression / Q000235:genetics; D006801:Humans; D051379:Mice; D032342:Muscle Cells / Q000166:cytology / Q000378:metabolism*; D009154:Mutation; D017570:MyoD Protein / Q000235:genetics / Q000378:metabolism; D018008:Myogenin / Q000378:metabolism; D018995:Myosin Heavy Chains / Q000378:metabolism; D041681:NIH 3T3 Cells; D010957:Plasmids / Q000235:genetics; D011485:Protein Binding; D011493:Protein Kinase C; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D014162:Transfection; D020798:Two-Hybrid System Techniques
C441622:CCNT2 protein, human; D056906:Cyclin T; D016213:Cyclins; D018076:DNA, Complementary; D017570:MyoD Protein; D018008:Myogenin; D011994:Recombinant Proteins; C061570:protein kinase N; D011505:Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; D011493:Protein Kinase C; C467969:CDK9 protein, human; D042863:Cyclin-Dependent Kinase 9; D018995:Myosin Heavy Chains