Cloning and characterization of a tomato GTPase-like gene related to yeast and Arabidopsis genes involved in vesicular transport.

The deduced translation product of a tomato cDNA derived from a gene expressed in a number of tomato tissues of different developmental stages contained sequence motifs characteristic of the GTPase superfamily of proteins. The sequence was closely related to the Sar1 protein of Saccharomyces cerevisiae, a protein essential for the formation of protein transport vesicles at the endoplasmic reticulum (ER) (A. Nakano and M. Muramatsu, Cell Biol 109 (1989): 2677-2691). From analysis of the GTPase superfamily gene sequences, including the tomato SAR-like gene, it is proposed that the SAR genes comprise a distinct GTPase subfamily, presumably with a common, essential function in vesicular transport.