Clifford Slayman, PhD

A long interest in the physical aspects of membrane transport processes—especially in phenomena related to charge transport—focuses now on proton “pumps,” proton-coupled cation transporters, and potassium channels in the plasma membranes of fungi, particularly Saccharomyces cerevisiae, Candida albicans (a pathogen), and Neurospora crassa. Structure-function analysis of proteins in these organisms is now possible, because of complete genome sequencing, and the laboratory is using site-directed mutagenesis and heterologous expression to analyze functional differences among analogous proteins in the three species. Novel and surprising properties have emerged, for example the development of enormous steady-state membrane voltages (exceeding 350 mV), mediation of active potassium transport by coupling to proton movements, and chloride channeling through potassium transporters. Also, a major current line of investigation is into the mechanisms by which small cationic peptides (so-called RAMPs) produced by a wide variety of plant and animal cells, become lethal to microorganisms, serving thereby as prototypes for new classes of therapeutic drugs. And finally, we have a new line, into the chemistry and morphogenetics of autophagy in fungi.