RAB PROTEINS OF DROSOPHILA-MELANOGASTER - NOVEL MEMBERS OF THE RAB-PROTEIN FAMILY

From a Drosophila head cDNA library, we isolated 9 cDNA clones, each o f which encodes a different member of Rab-protein family. Seven of the m (DRabs) have more than 80% amino acid identity to the corresponding members of mammalian Rab proteins. The other two proteins (DRabRP3 and 4) show low sequence similarity to any of the known Rab proteins. How ever, both contain all amino acids conserved in known Rabs. In additio n, DRabRP4 has strong GTP-binding activity, when synthesized in E. col i cells. These results indicate that DRabRPs are novel members of the Rab-protein family. Molecular phylogenetic analysis also supported thi s conclusion. (C) 1997 Federation of European Biochemical Societies.