Protein kinase C in the developing rat brain was investigated by a biochemical assay and by light-microscopic immunocytochemistry. The protein kinase was resolved on hydroxyapatite column chromatography into 3 fractions, designated types I, II, and III. Type I, with structure encoded by a gamma-sequence, was not detected early postnatally, maintained a low level of activity during the first week, which increased gradually, and reached its maximum around postnatal day 28. This type of enzyme was expressed specifically in nervous tissues, and was not found in any other tissues thus far tested. Type II enzyme activity, a mixture of the 2 subspecies encoded by the beta I- and beta II-sequences, was found at birth, increased rapidly, and reached a plateau level between postnatal days 14 and 28. This type was the predominant subspecies of protein kinase C in the brain. Type III, its structure encoded by the alpha-sequence, was also detected at birth, and reached its maximum level on postnatal day 7. Immunocytochemical studies with a monoclonal antibody, which recognized preferentially the type I enzyme, visualized the developmental pattern of type I subspecies in the Purkinje cell, a typical cell having a large quantity of type I protein kinase C.
Expression of protein kinase C (PKC) subspecies was studied in various human leukemia‐lymphoma cell lines. The PKC in most cell lines examined was resolved into two major fractions corresponding to type II (β‐sequence) and type III (α‐sequence) PKC of the rat brain. The amounts of these two subspecies greatly varied among the cell lines. Type I PKC (γ‐sequence) was expressed in none of the cell lines tested, but PKCs with undefined structures were frequently detected. The differential co‐expression of several PKC subspecies is presumably related to the state of cell differentiation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.