The rat lacrimal gland expresses the alpha isoform of PKC. Further evidence for the PMA-activated and phospholipid-independent protein kinase activity.
The molecular heterogeneity of protein kinase C (PKC) is now widely documented. In our first report, we characterized the rat lacrimal gland PKC along with a phorbol 12-myristate 13-acetate (PMA)-activated and phospholipid-independent protein kinase activity [Mauduit P., Zoukhri D. and Rossignol B. (1989) Fedn Eur. biochem. Socs Lett. 252, 5-11. In this work, we show that when the rat lacrimal gland cytosolic fraction is chromatographed on hydroxyapatite, only one peak of PKC activity can be detected. Comparison with a rat brain cytosolic fraction indicated that it is PKC-alpha which is expressed in the rat lacrimal gland. This result was confirmed by the use of polyclonal antibodies raised against rat brain PKC-alpha, beta and gamma isoforms. We also provide evidence that free arachidonic acid activates PKC, as does PMA, in a calcium and phospholipid-free system.
Zoukhri
D
D
Laboratoire de Biochimie des Transports Cellulaires, CNRS URA 1116, Université de Paris Sud, Orsay, France.
Pelosin
J M
JM
Mauduit
P
P
Chambaz
E
E
Sergheraert
C
C
Rossignol
B
B
D000470:Alkaloids / Q000494:pharmacology; D000818:Animals; D001095:Arachidonic Acids / Q000378:metabolism; D002848:Chromatography, DEAE-Cellulose; D004789:Enzyme Activation; D007765:Lacrimal Apparatus / Q000201:enzymology*; D008297:Male; D010743:Phospholipids / Q000378:metabolism*; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D019311:Staurosporine; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
D000470:Alkaloids; D001095:Arachidonic Acids; D010743:Phospholipids; D011493:Protein Kinase C; D019311:Staurosporine; D013755:Tetradecanoylphorbol Acetate