Abstract
Post-Golgi organelles play fundamental roles in various plant functions of higher order. However, our knowledge on molecular mechanisms of their biogenesis and trafficking system interconnecting them is still limited. We are studying molecular mechanisms of endocytic and vacuolar transport pathways with a special focus on plant-unique RAB and SNARE molecules. A. thaliana has two types of RAB5 members, conventional RAB5 and plant unique ARA6. Distinct subcellular localization of ARA6 from conventional RAB5 suggested functional differentiation between these two RAB5 groups (Ueda et al., 2004). On the other hand, VAMP727 is a plant-unique R-SNARE, which is characterized by an insertion of 20 amino acids in its N-terminal longin domain. We have already reported that VAMP727 forms a SNARE complex with VAM3, VTI11, and SYP51 on a subpopulation of PVCs closely associated with the vacuolar membrane (Ebine et al., 2008). In this meeting, we will report our recent results on a regulatory role of ARA6 in VAMP727 complex formation, and a role of ARA6 in environmental stress responses.
