Research article

Multiple domain insertions and losses in the evolution of the Rab prenylation complex

Rita Rasteiro and Jose B Pereira-Leal

Instituto Gulbenkian de Ciência, Apartado 14, P-2781-901 Oeiras Portugal

author email corresponding author email

BMC Evolutionary Biology 2007, 7:140doi:10.1186/1471-2148-7-140

Published:	17 August 2007

Abstract

Background

Rab proteins are regulators of vesicular trafficking, requiring a lipid modification for proper function, prenylation of C-terminal cysteines. This is catalysed by a complex of a catalytic heterodimer (Rab Geranylgeranyl Transferase – RabGGTase) and an accessory protein (Rab Escort Protein. REP). Components of this complex display domain insertions relative to paralogous proteins. The function of these inserted domains is unclear.

Results

We profiled the domain architecture of the components of the Rab prenylation complex in evolution. We identified the orthologues of the components of the Rab prenylation machinery in 43 organisms, representing the crown eukaryotic groups. We characterize in detail the domain structure of all these components and the phylogenetic relationships between the individual domains.

Conclusion

We found different domain insertions in different taxa, in α-subunits of RGGTase and REP. Our results suggest that there were multiple insertions, expansions and contractions in the evolution of this prenylation complex.