Induction and phosphorylation of protein kinase C-alpha and mitogen-activated protein kinase by hypoxia and by radiation in Chinese hamster V79 cells.
Protein kinase C (PKC) and mitogen-activated protein (MAP) kinase are protein-serine/threonine kinases which are important regulators of diverse cellular processes including metabolism, proliferation and differentiation. This study shows that both hypoxia and X irradiation of serum-deprived Chinese hamster V79 cells cause the induction and phosphorylation of the PKC-alpha isoform. The increased induction and phosphorylation of PKC occur mainly in the nuclear fraction. Unlike the PKC activator TPA, neither hypoxic nor radiation stress causes translocation of PKC-alpha from the cytosol to the membrane. The induction of PKC-alpha by hypoxia is accompanied by an increased expression of MAP kinase but, in contrast, this does not occur when PKC-alpha is induced by radiation. Radiation, like TPA, causes a complete redistribution of MAP kinase from the cytosol to the nucleus.
Hasan
N M
NM
Medical Research Council, Radiobiology Unit, Chilton, Didcot, Oxon, United Kingdom.
Parker
P J
PJ
Adams
G E
GE
D000818:Animals; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D002451:Cell Compartmentation / Q000528:radiation effects; D002460:Cell Line; D006224:Cricetinae; D003412:Cricetulus; D004790:Enzyme Induction / Q000528:radiation effects; D000860:Hypoxia / Q000201:enzymology*; D010766:Phosphorylation / Q000528:radiation effects; D010768:Phosphoserine / Q000378:metabolism; D010769:Phosphothreonine / Q000378:metabolism; D011493:Protein Kinase C / Q000378:metabolism*; D014965:X-Rays
D010769:Phosphothreonine; D010768:Phosphoserine; D011493:Protein Kinase C; D017871:Calcium-Calmodulin-Dependent Protein Kinases