Abstract
SNAREs (soluble N-ethylmaleimide sensitive factor attachment protein receptors) regulate specific membrane fusion between transport vesicles or organelles and target membranes in membrane traffic. AtVAM3 and AtPEP12 are Qa-SNAREs, which predominantly localize on the vacuolar membrane and the prevacuolar compartment (PVC), respectively. T-DNA insertion mutants for AtVAM3 (vam3) show pleiotropic phenotypes including semidwarfism and wavy leaves, although a loss-of-function mutant of AtPEP12 (pep12) exhibits no visible abnormality. By genetic analysis, we found that a double mutant for vam3 and pep12 is embryonic lethal. Moreover, promoter swapping analysis revealed that GFP-AtPEP12 driven by AtVAM3 promoter suppresses all phenotypes of vam3. These results suggest that the functions of AtVAM3 and AtPEP12 are redundant and interchangeable. We also report their precise subcellular localization observed by a high-performance confocal laser scanning microscope we developed.
