Differential expression of the beta I- and beta II-PKC subspecies in the postnatal developing rat brain; an immunocytochemical study.
Differential expression of protein kinase C subspecies, beta I- and beta II-PKC, derived from a single gene by alternative splicing was evidenced in the postnatal developing rat brain. Immunoblot analysis of the PKC subspecies in the whole developing brain showed that beta I-PKC was present at birth and then gradually increased, while beta II-PKC was not present at birth or on postnatal day 3, then increased rapidly from day 7 to the maximum value seen in the adult brain. Under light microscopy, beta I-PKC immunoreactivities seen at birth were the most intense in the brainstem and intense in the diagonal bundle and globus pallidus. beta I-PKC immunoreactivities in these neurons weakened from day 7 and disappeared in the adult brain, while in the cerebral cortex, triangular septal nucleus and pontine nucleus beta I-PKC immunoreactivities were week at birth and then gradually increased. beta II-PKC immunoreactivities were first visible in neurons on day 7 and increased progressively. beta I- and beta II-PKCs were not co-localized in a neuron, as far as examined. The immunoreactivities of beta I-PKC at birth were localized in growth cone-like structures as well as in the dendrites and perikarya. Similarly, alpha-PKC was also present at birth in the growth cone-like structure. Immunoblot analysis revealed that beta I-PKC was present at birth in the growth cone-rich fraction from the hindbrain but not in that from the forebrain, while alpha-PKC was found in the growth cone-rich fraction from both the forebrain and the hindbrain. beta II- and gamma-PKC were not detected in the growth cone-rich fraction from either forebrain or hindbrain. These findings suggest that beta I- and beta II-PKC play a role in different stages of development and in different neurons; both beta-subspecies may be involved in postnatal developing neuronal functions while only beta I-PKC plays functional roles in the growth cone, in the prenatal developmental stage.
Hirata
M
M
Department of Pharmacology, Kobe University School of Medicine, Japan.
Saito
N
N
Kono
M
M
Tanaka
C
C
D000375:Aging / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn / Q000254:growth & development / Q000378:metabolism*; D015153:Blotting, Western; D001921:Brain / Q000166:cytology / Q000254:growth & development / Q000378:metabolism*; D007150:Immunohistochemistry; D011493:Protein Kinase C / Q000145:classification / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D014018:Tissue Distribution
D011493:Protein Kinase C