Ribosomal protein L10A and signaling pathway.

ABSTRACT

Ribosome machinery in control of messenger RNA's (mRNAs) and several ribosomal proteins are in the small and large subunit of the ribosome. Various aspects of ribosomal proteins have related to cell growth, cell cycle, and diseases. Ribosomal protein L10A (RpL10A) in shrimp and fruit fly has been demonstrated to play a role in oogenesis. Interestingly, deletion RpL10A gene (RpL10Ab-/-) germ line clone of the fruit fly showed a loss of follicle cells surrounding the egg chamber, but nurse cells appeared normal. This phenotype is reminiscent of insulin receptor mutants (InR-/-). In contrast, over-expression of RpL10A in the eyes of the fruit flies resulted in abnormal ommatidia with a loss of red pigment in the center of the eyes. In this study, the abnormal rearrangements of nuclei and lack of cell membranes in those eyes were demonstrated. Furthermore, the expression of InR gene and the InR protein were extensively increased as determined by real-time PCR and immunohistochemistry, respectively. In addition, some insulin signaling mediators were also detected. The Akt and FOXO proteins were highly phosphorylated in the RpL10A over-expressed mutant. The results revealed that RpL10A induced over-expression of the insulin receptor and consequently activated in insulin signaling pathway which affects cell proliferation and we suggest RpL10A stimulates cell proliferation via the insulin signaling pathway.