Role of plasma as activator and cofactor in phosphorylation catalyzed by protein kinase C.
The purpose of this study was to investigate whether plasma can influence the phosphorylation of protein kinase C (PKC). Lysate samples were prepared from normal skin or melanoma tissue and were reacted with a PKC peptide substrate in the presence or absence of plasma. In normal skin tissue lysates, the phosphorylation rates were much lower than those in melanoma tissue lysates. However, the level of phosphorylated peptide was increased in both normal skin and melanoma tissue lysates if plasma was present. Phosphorylation rates in the samples taken from the centre of B16 melanoma tissue were lower than those in samples taken from the edge. Moreover, addition of activator and/or cofactors (diacylglycerol, phosphatidylserine and/or Ca2+) of PKC, or plasma to the lysates contaminated by plasma had no effect on phosphorylation rates for the peptide substrate. These results indicate that plasma can play a role of activator and cofactor for substrate phosphorylation.
Kang
Jeong-Hun
JH
CREST, Japan Science and Technology Corporation, Kawaguchi-shi, Saitama, Japan.
Asai
Daisuke
D
Oishi
Jun
J
Kawamura
Kenji
K
Toita
Riki
R
Jiang
Yuhua
Y
Mori
Takeshi
T
Niidome
Takuro
T
Katayama
Yoshiki
Y
D000818:Animals; D002384:Catalysis; D003067:Coenzymes / Q000737:chemistry / Q000502:physiology*; D004789:Enzyme Activation / Q000502:physiology; D008297:Male; D008546:Melanoma, Experimental / Q000201:enzymology; D051379:Mice; D010455:Peptides / Q000138:chemical synthesis / Q000378:metabolism; D010766:Phosphorylation; D010949:Plasma / Q000737:chemistry / Q000502:physiology*; D011493:Protein Kinase C / Q000737:chemistry / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology; D012867:Skin / Q000201:enzymology; D013379:Substrate Specificity / Q000502:physiology
D003067:Coenzymes; D010455:Peptides; D011493:Protein Kinase C