Prenylation of RabGTPases, Their Delivery to Membranes, and Rab Recycling - Ras Superfamily Small G Proteins: Biology and Mechanisms 2 - page 2

Chapter 1
Prenylation of RabGTPases, Their Delivery
to Membranes, and Rab Recycling

Roger S. Goody, Yaowen Wu, and Aymelt Itzen

Abstract Rab proteins, in common with many other Ras superfamily members,
need to be lipidated (in the case of Rab geranylgeranylated) at their C-terminus to
be able to interact with membranes. Here, we review the basic mechanism of
geranlygeranylation and then address the still unsolved question of how prenylated
Rabs are delivered to specific membranes. The evidence reviewed leads to a model
in which specifically localized guanine nucleotide exchange factors are an essential
component of the targeting mechanism, and that additional stabilizing interactions
are important in a number of cases, including effector interactions and positively
charged residues in the C-terminus in at least one case examined. Finally, there is
evidence that in some cases additional still unidentified factors are involved.

Keywords RabGTPases • Prenylation • Delivery • Localization • GEF • GDI •
GDF

1.1 Introduction

Intracellular vesicular transport is an important and essential aspect of the func-
tioning of eukaryotic cells. Transport between membrane-bound compartments
occurs via vesicles or tubular structures in a highly complex and tightly regulated