%0 Journal Article %T Expression of PKC Iota Affects Neuronal Differentiation of PC12 Cells at Least Partly Independent of Kinase Function %A Alana Doonachar %A Alan R. Schoenfeld %J CellBio %P 1-13 %@ 2325-7792 %D 2014 %I Scientific Research Publishing %R 10.4236/cellbio.2014.31001 %X Atypical PKC (aPKC) plays a role in establishing cell polarity and has been indicated in neuronal differentiation and polarization, including neurite formation in rat pheochromocytoma PC12 cells, albeit by unclear mechanisms. Here, the role of the aPKC isoform, PKC iota (PKC¦É), in the early neuronal differentiation of PC12 cells, was investigated. NGF-treated PC12 cells with stably expressed exogenous wild-type PKC¦É showed decreased expression of a neuroendocrine marker, increased expression of a neuronal marker and increased neurite formation. Stable expression of a kinase-inactive PKC¦É, but not constitutively active PKC¦É lacking a regulatory domain, had similar though less potent effects. Pharmacological inhibition of endogenous aPKC kinase activity in parental PC12 cells did not inhibit neurite formation, suggesting that some of the observed effects of PKC¦É expression on neuronal differentiation are kinase-independent. Interestingly, exogenous expression of wild-type and kinase-inactive PKC¦É had little effect on overall PKC¦É activity, but caused a decrease in PKC zeta (PKC¦Ć) kinase activity, suggesting an interplay between the two isoforms that may underlie the observed results. Overall, these findings suggest that in PC12 and perhaps other neuroendocrine precursor cells, PKC¦É influences an early differentiation decision between the neuroendocrine (chromaffin) and sympathetic neuron cell lineages, potentially by affecting PKC¦Ć function. %K Atypical PKC %K Neurite Outgrowth %K Neuronal Differentiation %K Neuroendocrine %K PC12 %K PKC Iota %U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=43365