Cloning of murine CDK9/PITALRE and its tissue-specific expression in development.
The cdc2-family of serine/threonine kinases and their binding partners recently were implicated in developmental roles. We previously cloned a cdc2-related kinase, cdk9/PITALRE, that is able to phosphorylate the retinoblastoma protein in vitro. We describe here the cloning and the characterization of the mouse homolog of cdk9/PITALRE. The murine cDNA is 98% identical with humans and is expressed at high levels in brain and kidney tissues. The kinase activity and protein expression of cdk9/PITALRE were highest in terminally differentiated tissues such as the muscle and brain. In situ immunohistology and immunofluorescence detected cdk9/PITALRE protein not only within terminally differentiated cells such as muscle and neuronal cells, but also in proliferating cells. C2C12 and P19 cells induced to differentiate along muscle and neural lineages peaked in cdk9/PITALRE kinase activity at the end of differentiation. These results suggest that, among other roles, cdk9/PITALRE plays a role not unlike cdk5 in the differentiation of certain cell types.
Bagella
L
L
Department of Pathology, Anatomy and Cell Biology, Sbarro Institute for Cancer Research and Molecular Medicine, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA.
MacLachlan
T K
TK
Buono
R J
RJ
Pisano
M M
MM
Giordano
A
A
De Luca
A
A
D000595:Amino Acid Sequence; D000818:Animals; D000918:Antibody Specificity; D002454:Cell Differentiation / Q000235:genetics; D002460:Cell Line; D003001:Cloning, Molecular; D042863:Cyclin-Dependent Kinase 9; D018076:DNA, Complementary / Q000737:chemistry / Q000302:isolation & purification; D004622:Embryo, Mammalian / Q000201:enzymology; D004789:Enzyme Activation; D005260:Female; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D015151:Immunoblotting; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D008969:Molecular Sequence Data; D009928:Organ Specificity / Q000235:genetics; D011494:Protein Kinases / Q000096:biosynthesis* / Q000235:genetics* / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
D018076:DNA, Complementary; D011494:Protein Kinases; C467969:CDK9 protein, human; C467972:Cdk9 protein, mouse; D042863:Cyclin-Dependent Kinase 9