AUTHOR=Hirano Tomoko , Sato Masa H. 

TITLE=Diverse Physiological Functions of FAB1 and Phosphatidylinositol 3,5-Bisphosphate in Plants

JOURNAL=Frontiers in Plant Science

VOLUME=Volume 10 - 2019

YEAR=2019

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2019.00274

DOI=10.3389/fpls.2019.00274

ISSN=1664-462X

ABSTRACT=Biological membranes are predominantly composed of structural glycerophospholipids such as phosphatidylcholine, phosphatidylethanolamine, and phosphatidylinositol. Of the membrane glycerophospholipids, phosphatidylinositol (PtdIns) and its phosphorylated derivatives (phosphoinositides) constitute a minor fraction that exert a wide variety of regulatory functions in eukaryotic cells. Phosphoinositides, which comprise 3 PtdIns  monophosphates, 2 PtdIns bisphosphates, and one PtdIns triphosphate, phosphorylate the hydroxy groups of the inositol head group of phosphatidylinositol by specific lipid kinases. Among the total phosphoinositides available in a cell, phosphatidylinositol 3,5-bisphosphate [PtdIns(3,5)P2] constitutes the smallest fraction; however, it is a crucial lipid in the animal and yeast membrane trafficking systems. In this review, we focus on the recent findings on the physiological functions of PtdIns(3,5)P2 and its catalyst enzyme—formation of aploid and binucleate cells (FAB1) —along with the regulatory proteins of FAB1 and the downstream effector proteins of PtdIns(3,5)P2 in Arabidopsis.