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This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: fj.07-101410v1 22/7/2405    most recent Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Loukin, S. Articles by Saimi, Y. PubMed PubMed Citation Articles by Loukin, S. Articles by Saimi, Y.

A genome-wide survey suggests an osmoprotective role for vacuolar Ca²⁺ release in cell wall-compromised yeast

Stephen Loukin^*,1, Xinliang Zhou^*, Ching Kung^*, and Yoshiro Saimi^*

^* Laboratory of Molecular Biology and

Department of Genetics, University of Wisconsin–Madison, Madison, Wisconsin, USA

¹Correspondence: Laboratory of Molecular Biology, University of Wisconsin–Madison, Madison, WI 53706, USA. E-mail: shloukin{at}wisc.edu

In yeast, osmotic upshock causes a release of vacuolar Ca²⁺ through the mechanosensitive transient receptor potential channel, Yvc1. We screened the collection of 4810 yeast gene deletants twice for alterations in this response in an attempt to find elements that regulate the amount of vacuolar Ca²⁺ or the Yvc1 channel. Severe overresponders and underresponders to upshock were further scrutinized for their calcium content with ⁴⁵Ca and their Yvc1 electrophysiological activities under patch-clamp. The severe underresponders have lower calcium content but no change in Yvc1 activity. The strong overresponders, most of which are deleted of genes involved in cell wall metabolism, have higher calcium content. Wall mutations are known to up-regulate Ca²⁺-calcineurin-dependent genes. It appears that stress on the cell wall induces Ca²⁺ accumulation, adaptively anticipating the need in defense or repair against future stress, including osmotic stress.—Loukin, S., Zhou, X., Kung, C., Saimi, Y. A genome-wide survey suggests an osmoprotective role for vacuolar Ca²⁺ release in cell wall-compromised yeast.

Key Words: Saccharomyces cerevisiae • Yvc1 • TRPY1 • transient receptor potential ion channel • CCH1 • calcineurin