Abstract
Rab GTPase is one of key regulators in membrane traffic. Rab11, a widely conserved Rab GTPase group among eukaryotes, has been remarkably expanded in land plants while yeast and animals possess a few Rab11 members. In Arabidopsis thaliana, 57 Rab GTPases are encoded in its genome, 26 of which are classified into the Rab11 group (RabA1-RabA6). It is already known that animal Rab11, which localizes on the recycling endosome, plays an important role in regulating various cellular functions. On the other hand, precise subcellular localization and function of plant Rab11 remain largely unknown. To reveal the molecular function and physiological significance of plant Rab11, we at first investigated subcellular localization of RabA1 subgroup consisting of 9 members (RabA1a-RabA1i), and found that RabA1 members acts on the mobile punctate structures beside TGN. Next, we generated transgenic plants expressing dominant-negative or constitutive-active mutant of a RabA1 member and analyzed the subcellular localization and effects on growth. Based on the results obtained from these experiments, we will discuss the transport pathway regulated by the RabA1 subgroup.
