Activation and distribution of rat parotid cAMP-dependent protein kinase following beta-adrenergic receptor stimulation in vitro.
The extent of activation of parotid protein kinase A (EC 2.7.1.37) isozymes was determined using dispersed cells and an 8-N3-[32P]-cAMP photoprobe. Cold-trap studies indicated that 40% of type I protein kinase A was activated following maximal beta-adrenergic receptor stimulation, whereas type II activation was less than 20%. Both cytosolic and microsomal type I activation occurred rapidly after stimulation and both remain activated throughout the entire secretory period. The dose-response relationship for the isotypes following beta-adrenergic receptor activation demonstrated a greater extent of type I activation at maximal concentration of agonist. Although protein kinase A may not be the only kinase involved in rat parotid amylase release, these findings add further evidence of a direct regulatory role for this kinase, with type I having potentially a greater role than type II.
Quissell
D O
DO
University of Colorado Health Sciences Center, Aurora 80012.
Deisher
L M
LM
Barzen
K A
KA
D000818:Animals; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects; D007527:Isoenzymes; D008297:Male; D010306:Parotid Gland / Q000201:enzymology*; D011494:Protein Kinases / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D011943:Receptors, Adrenergic, beta / Q000187:drug effects*
D007527:Isoenzymes; D011943:Receptors, Adrenergic, beta; D011494:Protein Kinases