Plant phosphatidylinositol 3-kinase

Phosphatidylinositol 3-kinase (PI3K) phosphorylates the D-3 position of phosphoinositides. In Arabidopsis, only one PI3K exists, which belongs to the class-III PI3K subfamily which makes phosphatidylinositol 3-phosphate (PtdIns3P). The single AtPI3K gene is essential for survival, since loss of its expression results in lethality. Although not much is known about the molecular mechanism of its function, recent studies show that plant PI3K is important for development and signaling, similar to yeast and animal systems. This includes involvement in endocytosis, reactive oxygen species (ROS) production, and transcriptional activity. Many more interesting stories about the role of this enzyme in the core of cellular activities of plants will be unfold as refined technologies are applied to study this important enzyme.