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Martha Cyert

Academic Appointments

Contact Information

  • Academic Offices
    Personal Information
    Email

Professional Snapshot

Honors and Awards

  • Terman Fellow, Stanford University (2000)
  • Scholar, Lucille P. Markey Charitable Trust (1997)

Professional Education

A.B.: Harvard University, Biochemistry (1980)
Ph D.: UCSF, Genetics (1988)

Postdoctoral Advisees

Allyson O'Donnell

Graduate & Fellowship Program Affiliations

Scientific Focus

Research Interests

Research in the Cyert lab focuses on mechanisms of Ca2+-dependent signaling using the unicellular eukaryote,Saccharomyces cerevisiae, as a model system. In particular, the functions of calcineurin, a Ca2+/calmodulin-regulated phosphatase are studied. Calcineurin, which is specifically inhibited by the immunosuppressant drugs FK506 and cyclosporin A, mediates many Ca2+-regulated processes in mammalian cells, including T-cell activation, heart valve development, cardiac hypertrophy, and some aspects of learning and memory. In several pathogenic fungi, calcineurin is required for virulence.

In yeast, calcineurin is activated in response to a number of different environmental conditions, including high temperature, exposure to ions (Na+/Li+, Mn2+, OH-), ER stress, and cell wall damage, and is required for cells to survive these conditions.
A major function of calcineurin is to activate gene expression, and studies using DNA microarrays identified more than one hundred genes whose transcription is induced by calcineurin. These genes encode products that function in cell wall biosynthesis, secretion, signal transduction and ion homeostasis, and allow cells to survive environmental stress.
Calcineurin alters gene expression by regulating the transcription factor, Crz1p. In response to stress, calcineurin dephosphorylates Crz1p, causing its rapid relocalization from the cytosol to the nucleus. This role of calcineurin is conserved in higher eukaryotes, where calcineurin similarly dephosphorylates the NFAT transcription factor to effect its translocation to the nucleus. Surprisingly, Crz1p and NFAT share little sequence similarity, although notably both contain a conserved calcineurin-docking motif (see below).
Recently, biochemical and proteomic approaches were used to identify two kinases that phosphorylate and negatively regulate Crz1p. These kinases modulate the signaling threshold required to activate calcineurin/Crz1p –dependent gene...

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