RAB3 PROTEINS - KEY PLAYERS IN THE CONTROL OF EXOCYTOSIS

Although some mechanistic aspects of exocytosis, such as fusion events , have been well documented by the technique of time-resolved membrane -capacitance measurement, it was only recently that new insights into the molecular mechanisms involved in the traffic of secretory vesicles were provided by the convergence of different fines of research. In t his review Lledo et al. present some of the recent findings concerning small GTPases of the Rab3 subfamily which regulate hormone release, t riggered by entry, of Ca2+, in endocrine and neuroendocrine cells. In view of these new results, Rab proteins might be considered as candida tes for inhibition or stimulation of specific steps involved in vesicl e traffic.