Protein kinase C signaling molecules regulate encystation of Acanthamoeba.

Protein kinase C (PKC) is involved in receptor desensitization, membrane biogenesis, transcription regulation, immune response mediation, and cell growth regulation. Results of ESTs analysis and microarray analysis of Acanthamoeba cysts revealed high expression of PKC during encystation of Acanthamoeba. PKC inhibitor, chelerythrine chloride, inhibited cyst maturation of Acanthamoeba. Through domain search analysis, we found 27 types of PKC genes from Acanthamoeba ESTs (AcPKC1-AcPKC27), all of which were defined as atypical PKC isoforms. Results of fluorescence microscopic analysis showed the localization of AcPKC in cell membranes or nuclear membranes during encystation. siRNA against AcPKC reduced the encystation efficiency of Acanthamoeba. These AcPKC may be involved in several signal transduction pathways, especially during encystation of Acanthamoeba.