Abstract
All eukaryotic cells comprise various single membrane-bound organelles, which are interconnected by the trafficking system mediated by vesicular and/or tubular membrane carriers. This system, membrane traffic, plays fundamental roles in various cellular functions including maintenance of organelle identity, transport and retention of organelle resident proteins, and intra- and inter-cellular signaling. RAB GTPases and SNARE molecules are evolutionary conserved key players regulating tethering and fusion steps between donor and target membranes, whose paralogous expansion appears to be closely associated with diversification of organelles and trafficking pathways. We have identified several plant-unique RAB and SNARE molecules, which could be involved in unique functions to plants. Our genetic, biochemical, and cell biological analyses have been revealing their interesting functions, which indicates that land plants have evolved a quite unique mechanism for the regulation of membrane traffic.
