Ron Cook (Benning lab)

Date & Location: December 10, 2019, at 12p; Room 168 Plant Biology Building

Subject: Phosphatidic acid phosphatases in chloroplast lipid metabolism

Abstract: Chloroplast membranes are unique in that they are not primarily composed of phospholipids. Instead, galactolipids comprise over 75% of chloroplast membrane lipids, thereby minimizing the phosphate requirement of plants. The galactolipids are synthesized from diacylglycerol (DAG) at the chloroplast inner envelop membrane (IEM). DAG in itself is a product of the dephosphorylation of phosphatidic acid (PA) by enzymes known as PA phosphatases. PA is assembled in both the IEM and the endoplasmic reticulum (ER). While chloroplast-derived PA is known to be dephosphorylated at the IEM by PA phosphatases, it is unclear whether ER-derived PA is imported into the IEM for dephosphorylation by these same enzymes, or whether it is dephosphorylated prior to being imported as DAG. Current research on the chloroplast-localized PA phosphatases LPPγ, LPPε1, and LPPε2 seeks to address these gaps in our understanding of how plants convert phospholipids into galactolipids.

Speaker Lab: Dr. Christoph Benning