The Daily Bulletin Archive

Please join the Biology Department and the Great Lakes Center for the seminar "The Trypanosome Lipin TbLpn and the Effect of Arginine Methylation on Its Enzymatic Activity," presented Michel Pelletier, associate professor and chair of the Biology Department at SUNY Brockport, on Monday, October 16, at 3:00 p.m. in Science and Mathematics Complex 151. Attendees are welcome to arrive at 2:30 p.m. to enjoy coffee and cookies before the seminar.

Abstract
Trypanosoma brucei, a parasitic protozoan, causes African sleeping sickness. The disease, native to sub-Saharan Africa, is transmitted by the tsetse fly to a mammalian host. Over 70,000 deaths a year are caused by the disease, but millions are at risk. In addition, the disease is fatal unless treated. Phospholipid biosynthesis plays an important role in the survival of T. brucei, especially phosphatidylcholine (PC) and phosphatidylethanolamine (PE). Most importantly, trypanosomes synthesize their phospholipids de novo. T. brucei lipin (TbLpn), a protein homologous to yeast and human lipin, has previously been identified. TbLpn catalyzes dephosphorylation of phosphatidic acid (PA) to form diacylglycerol (DAG) that can further be used for phospholipid synthesis. In addition, TbLpn contains methylated arginine residues in vivo and interacts with TbPRMTs, a class of trypanosome protein arginine methyltransferases. To determine the roles of arginine methylation on TbLpn enzymatic activity, three arginine residues predicted to undergo methylation, Arg-32, Arg-56, and Arg-703, were mutated to lysine. The mutant TbLpn protein was then expressed in Escherichia coli, purified, and its enzymatic activity assessed in vitro.