Clifford L. Slayman Professor of Cellular & Molecular Physiology » Physiology and Integrative Medical Biology » Microbiology » Molecular Cell Biology, Genetics and Development » A.B. Kenyon College 1958; Ph.D. Rockefeller University 1963 Our research into the physiological and molecular mechanisms of biological transport, carried out mainly on charge-dependent processes in the membranes of microorganisms, now focuses on potassium transfer processes in yeast membranes. Studies are currently being conducted on four distinct genes/proteins in Saccharomyces cerevisiae: TOK1, a bona fide K+ channel; TRK1, a high-affinity active carrier for K+; TRK2, a low-affinity K+ carrier; and NSC1, a non-selective cation channel in the yeast membrane, whose structural gene has not yet been identified. Current methods include gene deletion and forced expression, site-directed mutagenesis, patch recording, conventional microelectrode technology, chemical flux analysis, and fluorescence microscopy. Special efforts are being directed toward the TRK carriers, which are folded like primitive K+ channels, and which—in addition to mediating active potassium accumulation—also behave like chloride efflux channels, similarly to the excitatory amino acid transporters in mammalian nervous tissue. Potassium ions are important for metabolic stability, as well as for detailed membrane function, and results from Saccharomyces are equally applicable to pathogenic fungi of both medical and agricultural importance. We have therefore recently begun collaborative work on the human parasite Candida albicans, investigating the relationship between potassium transport and the organism’s susceptibility to natural antimicrobial peptides, particularly salivary histatins. Baev, D., et al. (2003). Killing of Candida albicans by human salivary histatin 5 is modulated, but not determined, by the potassium channel TOK1. Infect. Immun. 71:3251-3260. Bihler, H., Slayman, C.L., and Bertl, A. (2002). Low-affinity potassium uptake by Saccharomyces cerevisiae is mediated by NSC1, a calcium-blocked non-specific cation channel. Biochim. Biophys. Acta 1558:109-118. email clifford.slayman@yale.edu   website Slayman Home Page