Fungi; Physiology; Potassium Channels; Proton Pumps; Histatins
Cellular & Molecular Physiology: Membrane Biophysics | Membrane Proteins - Ion Channels | Membrane Proteins - Pumps and Transporters
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)
- Rivetta, A., Allen, K.E., Slayman, C.W., & Slayman, C.L., 2013. Coordination of K+ transporters in Neurospora: TRK1 is scarce and constitutive, while HAK1 is abundant and highly regulated. Eukar. Cell 12:684-696.
- Rivetta, A., Kuroda, T., & Slayman, C., 2011. Anion currents in yeast K+ transporters (TRK) characterize a structural homologue of ligand-gated ion channels. Pflügers Arch.— Europ.J.Physiol. 462:315-330.
- Miranda, M., Bashi, E., Vylkova, S., Edgerton, M., Slayman, C., & Rivetta, A., 2009. Conservation and dispersion of sequence and function in fungal TRK potassium transporters: Focus on Candida albicans. FEMS Yeast Res. 9: 278-292. PMID: 19175416
- Bertl A, Bihler H, Kettner C, Slayman CL. Electrophysiology in the eukaryotic model cell, Saccharomyces cerevisiae. Pflügers Archiv Eur J Physiol, 436:999-1013, 1998.
- Kuroda T, Bihler H, Bashi E, Slayman CL, Rivetta A. Chloride channel function in the yeast TRK-potassium transporters. J Membr Biol, 198:177-92, 2004.
- Baev D, Rivetta A, Vylkova S, Sun JN, Zeng G-F, Slayman CL, Edgerton M. The TRK1 potassium transporter is the critical effector for killing of Candida albicans by the cationic protein, Histatin 5. J Biol Chem, 279:55060-72, 2004.
- Rivetta A, Slayman CL, Kuroda T. Quantitative modeling of chloride conductance in yeast TRK potassium transporters. Biophys J, 89:2412-26, 2005.