Pkc53Eis the second conventional protein kinase C (PKC) gene expressed inDrosophilaphotoreceptors; 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 ofpkc53E-Bleads to light-dependent retinal degeneration. Interestingly, the knockdown ofpkc53Ealso 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 ofnorpAP24photoreceptors 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.