Poster: Enzymology

Abs # 239: Functional Characterization of Putative Phosphatidylcholine-Hydrolyzing Phospholipase C in Arabidopsis

Presenter:	Wood, Tara B., tbw6699@ksu.edu
Authors	Wood, Tara B. (A)   Qin, Chunbo  (B)   Wang, Xuemin  (A)
Affiliations:	(A): Department of Biochemistry, Kansas State University (B): Cornell University Medical Center

Phospholipases are enzymes that hydrolyze phospholipids. These enzymes are involved in many cellular processes including signal transduction, cytoskeletal rearrangements, vesicular trafficking, and lipid degradation. Phosphatidylcholine-hydrolyzing phospholipase C (PC-PLC) hydrolyzes phospholipids to diacylglycerol and phosphorylated head groups. The activity of PC-PLC has been reported in plant tissues, but the molecular nature of this enzyme is unknown. Six genes have been identified in Arabidopsis which show 41% amino acid sequence similarity to gram-negative bacterial phosphatidylcholine-hydrolyzing PLCs. Full-length cDNAs have been cloned for three of these genes and antibodies have been made against an expressed protein. Homozygous gene knockout mutants have been isolated and confirmed for all six genes, and in addition, we have overexpressed one of these genes. Characterization of the mutants and expressed proteins is underway and will help determine the catalytic, cellular and physiological functions of these enzymes.