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Your Environment. Your Health.

Membrane Signaling Group

David L. Armstrong, Ph.D.
David L. Armstrong, Ph.D.
Group Leader
Tel (919) 541-0062
armstro3@niehs.nih.gov
111 T W Alexander Dr
Rall Building
Research Triangle Park, NC 27709

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Research Summary 

The Membrane Signaling Group (MSG) studies the regulation of ion channel proteins by hormonal signaling through G proteins, calcium and protein phosphorylation.

This graphic is an illustration of an idealized cell surrounded by its surface membrane. The two ion channel protein pores (cylindrical pipes) at the top of the cell span the membrane. The open pore allows ions (green spheres) to diffuse through, while the other is closed because it has been phosphorylated.


Many environmental toxicants impair human health by disrupting these signaling cascades. Mutations in the genes encoding ion channels also increase human susceptibility to many diseases. The MSG focuses on the voltage-activated channels that are selectively permeable to calcium or to potassium and uses the patch clamp technique to study channel protein function and regulation at the molecular level in live cells in real time. The work is being continued at three levels of biological organization. At the molecular level, the group studies the structural basis of channel regulation by protein phosphorylation. At the cellular level, the ion channels are being used as a quantitative assay system to investigate the mechanisms linking G proteins to the protein kinases and phosphatases which regulate channel activity. Finally, at the physiological level the group has begun to explore the significance of the signaling pathways for neuronal development, function, and survival. The goal of the Membrane Signaling Group is to determine how disruption of these signal transduction pathways by pathogens and environmental toxicants contributes to the degenerative diseases which increasingly debilitate our aging population.

Major areas of research:

  • Ion channel regulation by G protein signaling, calcium and phosphorylation
  • Protein phosphatase regulation by hormones and toxicants
  • Thyroid hormone signaling

Current projects:

  • endocrine disruption of thyroid hormone signaling in the nervous system
  • CaV 1.2 channel regulation by calcium-dependent kinases and phosphatases
  • hERG channel regulation by Rho GTPases and protein phosphorylation
  • Rac GTPase signaling through the Ser/Thr protein phosphatase, PP5, in brain
  • acute effects of ethanol exposure on brain function

David L. Armstrong, Ph.D., serves as group leader of the Membrane Signaling Group. Armstrong was trained in neurophysiology at the California Institute of Technology and received his Ph.D. in 1978. Following postdoctoral research at University College London, the Salk Institute and the University of California in Los Angeles, Armstrong joined the intramural research program within NIEHS as Head of the Membrane Signaling Group in 1987. He became a tenured Research Physiologist in 1994.

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