Letter to the Editor

Study of the Mechanism of Small GTPase Ras-dva Intracellular Localization

M. B. Tereshina1 #, V. V. Belousov1 and A. G. Zaraisky1

#Phone: (495) 3368611; fax: (495) 3363622; e-mail: ma-treshka@yandex.ru

1Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Mikluho-Maklaya 16/10, Moscow, 117997, Russia

Received: April 13, 2007;  in final form: April 17, 2007

Abstract.  An analysis of amino acid sequences of small GTPases of the Ras-dva family allowed us to determine the C-terminal prenylation motif, which could be responsible for the membrane localization of these proteins. We demonstrated using the in vivo EGFP-tracing that the Ras-dva small GTPases from the Xenopus laevis embryo-cells and NIH-3T3 fibroblasts are localized on both plasma membranes and endomembranes (the endoplasmic reticulum, the Golgi apparatus, and vesicles). At the same time, the replacement of Cys residue, the SH group of which must be theoretically farnesylated, in the C-terminal prenylation motif of the Ras-dva small GTPase by the Ser residue prevented the membrane localization of the protein. These results indicate that the C-terminal prenylation site is critical for the membrane localization of small Ras-dva GTPases.

Key words:  intracellular localization; prenylation site; Ras-dva family; small GTPases

Russian Journal of Bioorganic Chemistry 2007, 33(5): 534-536