Use of microphysiometry for analysis of heterologous ion channels expressed in yeast

Karen M. Hahnenberger, Mark Krystal, Kim Esposito, Weimin Tang, Stephen Kurtz

Research output: Contribution to journalArticlepeer-review

14 Scopus citations


Measurement of extracellular acidification rates by microphysiometry provides a means to analyze the function of ion channels expressed in yeast cells. These measurements depend on the proton pumping action of the H -ATPase, a central component of the yeast plasma membrane. We used microphysiometry to analyze the activity of two ion channels expressed in yeast. In one example, an inwardly rectifying K* channel, gplRKI, provides a potassium uptake function when expressed in a potassium transporter-defective yeast strain. Rates of acidification in gplRKI-expressing cells directly reflect channel function. Addition of cesium, an inhibitor of gplRKI activity, results in an immediate reduction in acidification rates. In a second example, expression of a nonselective cation channel, the influenza virus M2 protein, is believed to interfere with the maintenance of the electrochemical proton gradient by the H -ATPase. In cells expressing the M2 channel, addition of inhibitors increases the rate of proton extrusion. Moreover, functional differences between two M2 inhibitors, amantadine and BL-1743, are distinguished by the microphysiometer. This application demonstrates the utility of the microphysiometer for functional studies of ion channels; it is adaptable to a screening process for compounds that modulate ion channel activity.

Original languageEnglish (US)
Pages (from-to)880-883
Number of pages4
JournalNature biotechnology
Issue number7
StatePublished - Jul 1996
Externally publishedYes

ASJC Scopus subject areas

  • Biotechnology
  • Bioengineering
  • Biomedical Engineering
  • Applied Microbiology and Biotechnology
  • Molecular Medicine


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