Professor, Department of Biomedical Sciences
Colorado State University
MM Tamkun PubMed
Program in Cell and Molecular Biology
Program in Molecular, Cellular and Integrative Neurosciences
1976, B.A. (Microbiology and Zoology) University of South Florida,Tampa, Florida
1979, M.A. (Zoology) University of South Florida, Tampa, Florida; Laboratory of David Hessinger, Department of Biology; Masters Thesis Title: The Isolation and Characterization of a Hemolytic and Lethal Protein from Portuguese Man-of-War (Physalia physalis) Nematocyst Venom
1983, Ph.D. (Pharmacology) University of Washington, Seattle, Washington; Laboratory of William Catterall, Department of Pharmacology; PhD Dissertation Title: Reconstitution of the Voltage-sensitive Sodium Channel from Purified Components
1984-87, Postdoctoral Fellow (Cell & Mol. Biol.) The Johns Hopkins University, Baltimore, MD; Laboratory of Douglas Fambrough, Department of Biology; Research Topic: Cell and Molecular Biology of the Neuronal (Na++K+)-ATPase
Primary teaching activities include organizing and lecturing in BMS 500 -- Mammalian Physiology, lecturing in neuroscience courses, and participating in various journal clubs. This formal teaching involves excitable membrane molecular biology and physiology as it relates to nerve and muscle function. However, most of the teaching activity is centered in the research laboratory. Instruction here runs from the postdoctoral to the undergraduate level; for the Tamkun laboratory contains postdoctoral fellows, graduate students, and undergraduates pursuing independent research projects.
High Resolution Cell Biology of Voltage-gated Ion Channels
I have been studying the plasma membrane and voltage-gated ion channels throughout most of my career. My membrane interests began as an undergraduate at the Univ. of South Florida where I studied how sea anenome and jellyfish venoms attack cellular membranes. This lead to an interest in neuronal membrane pharmacology and in 1979 I moved to Seattle to pursue a PhD in Pharmacology at the Univ. of Washington. My ion channel experience began with the purification and reconstitution of purified voltage-gated Na+ channel subunits as a graduate student in the lab of William Catterall and most of my graduate research training was in membrane protein biochemistry. Upon finishing the PhD in 1983 I studied the cell and molecular biology of the sodium/potassium ATPase in sensory neurons in the lab of Doug Fambrough at Johns Hopkins University. Once in my own laboratory as an Assistant Professor in the Department of Molecular Physiology and Biophysics at Vanderbilt Medical School I focused on voltage-gated K+ channel cloning, mutagenesis and heterologous expression for many years. Most of this research was targeted towards K+ channels in the cardiovascular system. My group also discovered the second Na+ channel gene family that is now known to be involved in Na+ sensing and transport as opposed to initiating action potentials. I was tenured and promoted to Associate Professor after six years and promoted to full professor at year nine. I relocated to Colorado State University as a tenured Full Professor in 1997.
I believe the next challenge in ion channel research is to understand the regulation of cell surface expression in nerve and muscle. Thus, many of my current efforts examine ion channel trafficking and cell surface localization mechanisms as well as the relationship between location and function. After extensive retooling of the lab, my group now uses confocal and TIRF-based live cell imaging to examine trafficking mechanisms and single channel diffusion. Simultaneous imaging/voltage-clamp approaches are used to study channel activity as a function of cell surface location. We are currently working with fluorescent protein and epitope-tagged Kv, Trp and Nav channels. Given our recent discovery of the relationship between non-conducting Kv2.1 channels, the endoplasmic reticulum and membrane protein trafficking my research interests are now expanding into neuronal cell biology.
Important advances in Biomedical Sciences are often through interdisciplinary approaches. The Tamkun (Biomedical Sciences) and Krapf (Electrical and Computer Engineering) labs have had a fruitful collaboration within CSU for the past four years. This collaboration has been successful because it represents a merger of ion channel molecular physiology with single molecule statistical physics. Much of our recent progress would not have been possible had the Tamkun and Krapf groups not worked together.
Positions and Employment
1978-79 Research Technician, Department of Biochemistry, Univ. of South Florida, Tampa, FL
1987-93 Assistant Professor, Department of Molecular Physiology and Biophysics, Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN
1993-96 Associate Professor (tenured), Department of Molecular Physiology and Biophysics, Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN
1996-97 Professor (tenured), Department of Molecular Physiology and Biophysics, Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN
1997-present Professor (tenured), Departments of Biomedical Sciences and Biochemistry and Molecular Biology, Colorado State University, Ft. Collins, CO
2010-2013 Associate Director, Molecular, Cellular and Integrative Neuroscience Program, Colorado State University, Ft. Collins, CO
2010-2014 Main Campus Facilities Director, Department of Biomedical Sciences, Colorado State University, Ft. Collins, CO
2014-present Director, Molecular, Cellular and Integrative Neuroscience Program, Colorado State University, Ft. Collins, CO
AHA Cell Signaling II Study Section, 1996-98; NIH Cardiovascular A Study Section, 1998-03. Ad Hoc reviewer for multiple NIH and international grant review panels, 1996-present. Manuscript reviewer for multiple biomedical journals, 1988-present.
NIH Predoctoral Training Grant. 1981-1983; Postdoctoral Fellowship, Muscular Dystrophy Association, 1984-1986; Postdoctoral Fellowship, NIH, 1984-1987, declined; New Investigator Award, American Heart Association, Tennessee Affiliate. 1988-1990; Established Investigator Award, American Heart Association, 1991-1996. Outstanding Advising Award in Graduate Education, Colorado State Univ. 2004 and 2011.