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A conventional PKC critical for both the light-dependent and the light-independent regulation of the actin cytoskeleton in Drosophila photoreceptors

Pkc53E is the second conventional protein kinase C (PKC) gene expressed in Drosophila photoreceptors; it encodes at least six transcripts generating four distinct protein isoforms including Pkc53E-B whose mRNA is preferentially expressed in photoreceptors. By characterizing transgenic lines expressi...

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Detalles Bibliográficos
Autores principales: Shieh, Bih-Hwa, Sun, Wesley, Ferng, Darwin
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Society for Biochemistry and Molecular Biology 2023
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10318518/
https://www.ncbi.nlm.nih.gov/pubmed/37201584
http://dx.doi.org/10.1016/j.jbc.2023.104822
Descripción
Sumario:Pkc53E is the second conventional protein kinase C (PKC) gene expressed in Drosophila photoreceptors; it encodes at least six transcripts generating four distinct protein isoforms including Pkc53E-B whose mRNA is preferentially expressed in photoreceptors. By characterizing transgenic lines expressing Pkc53E-B-GFP, we show Pkc53E-B is localized in the cytosol and rhabdomeres of photoreceptors, and the rhabdomeric localization appears dependent on the diurnal rhythm. A loss of function of pkc53E-B leads to light-dependent retinal degeneration. Interestingly, the knockdown of pkc53E also impacted the actin cytoskeleton of rhabdomeres in a light-independent manner. Here the Actin-GFP reporter is mislocalized and accumulated at the base of the rhabdomere, suggesting that Pkc53E regulates depolymerization of the actin microfilament. We explored the light-dependent regulation of Pkc53E and demonstrated that activation of Pkc53 E can be independent of the phospholipase C PLCβ4/NorpA as degeneration of norpA(P24) photoreceptors was enhanced by a reduced Pkc53E activity. We further show that the activation of Pkc53E may involve the activation of Plc21C by Gqα. Taken together, Pkc53E-B appears to exert both constitutive and light-regulated activity to promote the maintenance of photoreceptors possibly by regulating the actin cytoskeleton.