Our research into the molecular mechanisms of charge-dependent transport across biological membranes is directed toward two classes of proton pumps (P-type and V-type), a family of proton-coupled potassium transporters (TRK proteins), and a peculiar group of potassium channels which form as intramembrane homodimers (TOKs). All of these are studied in microorganisms, especially fungi, made accessible by full-genome sequences and by advanced electrophysiological techniques. A new, completely unexpected, direction for this research as been the investigation of interactions between specific membrane proteins and the rapidly growing catalogue of small proteins known as “host-defense peptides” or Ribosomally synthesized AntiMicrobial peptides (“RAMPs”). Some of these kill microorganisms by directly forming membrane pores, but more act by stealth, subverting the functions of surface proteins by reaction from the cell interior. One group of RAMPs, the salivary histatins, kills each of our three current “model” organisms: Candida albicans, Saccharomyces cerevisiae, and Neurospora crassa, by a different molecular route.
Specialized Terms: Charge-dependent Transport; Proton Pumps; Potassium channels; Ribosomally Synthesized AntiMicrobial Peptides (RAMPs)
Fungi; Physiology; Potassium Channels; Proton Pumps; Histatins