DESCRIPTION (provided by candidate) Dr. Ohnn Nahm is a nephrology fellow at the Johns Hopkins School of Medicine and will be appointed as a junior faculty member in July 2002 after completing the clinical part of his nephrology fellowship training. The ultimate goal for his career is to develop into an independent physician-scientist in the field of renal medicine, and to conduct cutting edge molecular research on the molecular mechanism of kidney cell survival under stressful conditions. The nephrology division at Johns Hopkins will provide an ideal environment for his career as a physician-scientist. In preparation for this goal, Dr. Nahm has spent the first three years of his nephrology fellowship in the laboratory of Dr. H. Moo Kwon studying molecular mechanisms responsible for renal cell survival under hypertonic stress. Recently, he discovered amino acid transport system A 2 (ATA2) mRNA to be significantly upregulated in cultured renal cells as well as in kidney and brain of animals during acute hypertonic stress. He plans to pursue the molecular mechanism of how ATA2 gene is regulated by changes in extracellular tonicity. In addition, he will delineate the role of ATA2 activation in cell survival during acute hypertonic stress. The outcome of this study will lead to the discovery of a novel molecular pathway that underlies the early cell adaptation during hypertonic stress. This study will also contribute to a better understanding on the adaptive mechanism of brain cells during pathologic changes in serum osmolality, which is essential for management of patients with hyper-or hyponatremia. During the entire funding period, he will be under the meticulous supervision of Dr. H. Moo Kwon, who is one of the most distinguished scientists in the field of transcriptional regulation of compatible osmolyte genes. Dr. Nahm?s research will also be closely guided by Dr. Sandra E. Guggino, who has pioneered cyclic nucleotide-dependent cationic channels in renal and intestinal epithelial cells. In addition to laboratory research, the proposed program is designed to include attendance at state-of-the-art biomedical seminars and molecular biology lectures to provide him a thorough training in molecular biology and scientific methods. At the end of the award period, Dr. Nahm will have acquired the expertise to become an independent investigator with the means to apply for grants to independently conduct research.