Different regulation of Purkinje cell dendritic development in cerebellar slice cultures by protein kinase Cα and ‐β

Abstract

Activity of protein kinase C (PKC), and in particular the PKCgamma-isoform, has been shown to strongly affect and regulate Purkinje cell dendritic development, suggesting an important role for PKC in activity-dependent Purkinje cell maturation. In this study we have analyzed the role of two additional Ca(2+)-dependent PKC isoforms, PKCalpha and -beta, in Purkinje cell survival and dendritic morphology in slice cultures using mice deficient in the respective enzymes. Pharmacological PKC activation strongly reduced basal Purkinje cell dendritic growth in wild-type mice whereas PKC inhibition promoted branching. Purkinje cells from mice deficient in PKCbeta, which is expressed in two splice forms by granule but not Purkinje cells, did not yield measurable morphological differences compared to respective wild-type cells under either experimental condition. In contrast, Purkinje cell dendrites in cultures from PKCalpha-deficient mice were clearly protected from the negative effects on dendritic growth of pharmacological PKC activation and showed an increased branching response to PKC inhibition as compared to wild-type cells. Together with our previous work on the role of PKCgamma, these data support a model predicting that normal Purkinje cell dendritic growth is mainly regulated by the PKCgamma-isoform, which is highly activated by developmental processes. The PKCalpha isoform in this model forms a reserve pool, which only becomes activated upon strong stimulation and then contributes to the limitation of dendritic growth. The PKCbeta isoform appears to not be involved in the signaling cascades regulating Purkinje cell dendritic maturation in cerebellar slice cultures.

Protein Kinase C Phosphorylation of a γ-Protocadherin C-terminal Lipid Binding Domain Regulates Focal Adhesion Kinase Inhibition and Dendrite Arborization

“…In addition to its effects on ␥-Pcdh function shown here, PKC is well known to be a negative downstream regulator of dendrite arborization (9,34,35,38,39). Consistent with this, broad activation of PKC by PMA reduced arborization to low levels regardless of which construct was expressed (Fig.…”

“…In support of this, although Gö6983 treatment did not enhance branching further in neurons expressing A3-S/A, PMA did reduce branching to low levels in these neurons. In any case, PKC is known to regulate dendrite arborization in multiple neuronal subtypes (34,35,38,39); given the widespread neural expression of the ␥-Pcdhs (9, 17, 21), our identification of Ser-922 as a PKC target may thus have broad relevance to PKC signaling and dendrite development throughout the brain.…”

Impaired Motor Learning in the Vestibulo-Ocular Reflex in Mice with Multiple Climbing Fiber Input to Cerebellar Purkinje Cells

“…The ␣ and ␤ isoforms are broadly expressed in the brain throughout life and play important roles in such fundamental functions as neurotransmitter release, synaptic plasticity, neurite development, and the regulation of neurotransmitter receptor clustering and internalization (Cambray-Deakin et al, 1990;Ben-Shlomo et al, 1991;Coffey et al, 1993;Brandon et al, 1999;Fan et al, 2002;Gundlfinger et al, 2003;Leitges et al, 2004;Tatsukawa et al, 2006) (for review, see Tanaka and Saito, 1992;Silinsky and Searl, 2003). In contrast, the ␥ isoform of PKC is expressed in only a few specific types of neurons in the brain, such as the Purkinje cells in the cerebellum, pyramidal and granule cells in the hippocampus, and lamina II neurons in the dorsal horn of the spinal cord Tanaka and Saito, 1992;Van Der Zee et al, 1997).…”

Haplotypes in the gene encoding protein kinase c-beta (PRKCB1) on chromosome 16 are associated with autism

“…PRKCB1-2 is most predominantly found in the synaptic endings of the parallel fibers of the granule cells. 42 This isoform of the protein kinase C family plays a central role in the regulation of synaptic transmission. 51 56 showed that granule neurons play a role in Purkinje cell development.…”

“…Results were consistent over all analysis programs with comparable significance levels (P ¼ 0.005 for TDTPHASE and P ¼ 0.002 for PDTPHASE, respectively). The three most positive SNPs 128, 136 (hCV11192725) and 140 (hCV946275) are all intragenic for the PRKCB1 gene, which plays a vital role in the regulation of synaptic function, 42 making it a reasonable positional and functional candidate. Another single SNP (SNP 73, hCV789442) located within the OTOA gene also showed a nominal significant Pvalue (P ¼ 0.01).…”