Functional characterization of ribosomal P1/P2 proteins in human cells

Francisco Martinez-Azorin (1) , Miguel Remacha , Juan P.G. Ballesta

1 CBMSO - Centro de Biología Molecular Severo Ochoa [Madrid]

The stalk is a large ribosomal subunit domain that regulates translation. In this study, the role of the ribosomal stalk P proteins in modulating ribosomal activity has been investigated in human cells using RNAi. A strong down-regulation of P2 mRNA and a drastic reduction of P2 protein in a stable human cell line was achieved using a Dox-inducible system. Interestingly, the amount of P1 protein was similarly reduced in these cells, in contrast to the expression of P1 mRNA. The loss of P1/P2 proteins produced a reduction in the growth rate of these cells, as well as an altered polysome pattern with reduced translation efficiency but without affecting the free 40S/60S subunit ratio. A decrease in the ribosomal subunit joining capacity was also observed. These data indicate that P1/P2 proteins modulates cytoplasmic translation by influencing the interaction between subunits, thereby regulating the rate of cell proliferation.

Mots clés: Life Sciences

Francisco Martinez-Azorin, Miguel Remacha, Juan P.G. Ballesta. Functional characterization of ribosomal P1/P2 proteins in human cells. Biochemical Journal, 2008, 413 (3), pp.527-534. ⟨10.1042/BJ20080049⟩. ⟨hal-00478947⟩