title: Characterization and androgenic regulation of soluble protein kinases and protein phosphorylation in rat ventral prostate gland.
abstract: The soluble protein kinase activities for protamine and casein, the histone kinases modulated by cAMP or Ca2+ and phospholipid, as well as the phosphorylation patterns of endogenous proteins were measured in rat ventral prostates from normal adults, castrates, and dihydrotestosterone-treated castrates. In normal prostate, the ratio of cAMP-dependent type I and II kinases was approximately 1:5. After a 3-week period of castration-induced regression, the concentrations of both enzymes were increased, but on a total organ basis, type I was decreased to 56%, while type II was reduced to 20% of normal levels. Casein kinase activity in unfractionated cytosol was not significantly altered by castration but when partially resolved into type I and II enzymes, there appeared to be a selective reduction in the type I component. In contrast, the total organ activities of protamine kinase or Ca2+-activated, phospholipid-dependent kinase, two measures of protein kinase C enzyme, were significantly increased (64 and 71%, respectively) above sham controls in regressed organs of castrates. All of the castration-induced changes in protein kinases were restored toward normal by dihydrotestosterone treatment. Castration effects on protein kinase C and the cAMP-dependent kinases appeared to be manifest in the phosphorylation of endogenous proteins. Castration resulted in a qualitative shift in the cAMP-dependent phosphorylation patterns as measured by gel electrophoresis, with increases in four major bands and decreases in two others, whereas the Ca2+-activated, phospholipid-dependent phosphorylation patterns were all enhanced. It is concluded that the androgenic regulation of protein kinase C differed qualitatively from that of other kinases, and its activation upon withdrawal of the androgenic stimulus may be involved in autophagic mechanisms in the prostate.
authors.forename: J P
authors.initials: JP
authors.lastname: Durham
authors.forename: F R
authors.initials: FR
authors.lastname: Butcher
authors.forename: T S
authors.initials: TS
authors.lastname: Teoh
authors.forename: R
authors.initials: R
authors.lastname: Miller
authors.forename: M G
authors.initials: MG
authors.lastname: Mawhinney
mesh_terms: D000728:Androgens / Q000494:pharmacology*; D000818:Animals; D047388:Casein Kinases; D002369:Castration; D002848:Chromatography, DEAE-Cellulose; D013196:Dihydrotestosterone / Q000494:pharmacology; D008297:Male; D010766:Phosphorylation; D011467:Prostate / Q000378:metabolism*; D011493:Protein Kinase C / Q000032:analysis; D011494:Protein Kinases / Q000032:analysis*; D011506:Proteins / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012995:Solubility
chemical_list: D000728:Androgens; D011506:Proteins; D013196:Dihydrotestosterone; D011494:Protein Kinases; D047388:Casein Kinases; D011493:Protein Kinase C