9603360 Frohman This award supports a two year collaborative research project between Professor Michael Frohman of the State University of New York (SUNY) at Stony Brook and Professor Yoshinori Nozawa of the Gifu University School of Medicine in Japan. The project will investigate the biochemical, cellular, and physiological roles of Phospholipase D (PLD), an enzyme thought to be involved in signal transduction, vesicular trafficking, and the control of cell division. The major goals of this project are: 1) to continue structure-function experiments using site-directed mutagenesis to identify amino acids required for interaction with cofactors such as protein kinase C and small G- proteins, and intracellular localization; and 2) to determine whether PLD1 or 2 are activated by stimulation of specific signal transduction pathways in well characterized cell lines, and whether such activation is necessary or sufficient to generate the subsequent cellular responses that have been ascribed to PLD activation in general. The project brings together the efforts of two laboratories that have constituted different parts of the process. The Americans have extensive experience with standard and advanced molecular biology techniques, microinjection of plasmids and proteins into cells, embryonic in situ hybridization, and transgenic mouse technology. The Japanese have been using approaches to study PLD for a decade and have extensive experience with a wide variety of pharmacological PLD activators and inhibitors, and with measuring the cellular consequences correlated with PLD activation, such as serotonin secretion, mast cell degranulation, and diacylglycerol production. PLD activation has been linked to a wide variety of normal physiological and disease processes in many different kinds of cells and tissues. Results of the research will provide realistic expectation about the advantages and limitation of the different model systems. This would serve as the basi s to determine which models should be implemented. Through the exchange of ideas and technology, this project will broaden our base of basic knowledge and promote international understanding and cooperation. ***
