Nature of the intrinsic protein kinases involved in phosphorylation of non-histone proteins in intact prostatic nuclei: further identification of androgen-sensitive protein kinase reactions.
Nuclei isolated from rat ventral prostate contain a number of messenger-dependent and -independent protein kinases. Studies were undertaken to determine the relative contribution of these protein kinases in phosphorylation of non-histone proteins (NHPs) in isolated nuclei. The data suggest that messenger-dependent protein kinases such as those dependent on cAMP or Ca2+/calmodulin or Ca2+/phospholipid may be present in very small amounts in intact isolated nuclei, and thus appear not to be significantly involved in phosphorylation of endogenous NHPs. Messenger-independent nuclear associated protein kinases PK-N1 and PK-N2 are known to catalyze the phosphorylation of NHPs in vitro (Goueli Sa, et al., Eur J Biochem 113: 45-51, 1980). Of these, the intrinsic heparin-sensitive PK-N2 as compared with heparin-insensitive PK-N1 appeared to be the predominant protein kinase engaged in phosphorylation of NHPs in intact nuclei. About 78-88% of NHP phosphorylation in intact nuclei was inhibited by heparin suggesting that the remaining 12-22% phosphorylation of NHPs was catalyzed via the heparin-insensitive protein kinase(s). Further, the data provide additional evidence that heparin-sensitive PK-N2 is the one that is most responsive to androgenic status in the animal.
Goueli
S A
SA
Cellular and Molecular Biochemistry Laboratory, University of Minnesota, Minneapolis.
Ahmed
K
K
D000728:Androgens / Q000494:pharmacology*; D000818:Animals; D001345:Autoradiography; D002467:Cell Nucleus / Q000187:drug effects / Q000201:enzymology; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism*; D004586:Electrophoresis; D006493:Heparin / Q000494:pharmacology; D008297:Male; D010766:Phosphorylation; D011467:Prostate / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D011494:Protein Kinases / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D000728:Androgens; D002868:Chromosomal Proteins, Non-Histone; D006493:Heparin; D011494:Protein Kinases; C036749:protein kinase NI; C026813:protein kinase NII