Regulation of Trk-dependent potassium transport by the calcineurin pathway involves the Hal5 kinase

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• 作者：Carlos Casado ; Lynne Yenush ; Carmen Melero ; Marí ; a del Carmen Ruiz ; Raquel Serrano ; Jorge Pé ; rez-Valle ; Joaquí ; n Ariñ ; o ; José ; Ramos
• 关键词：High-affinity potassium transport ; Trk1 ; Gene expression ; Saccharomyces cerevisiae
• 刊名：FEBS Letters
• 出版年：2010
• 出版时间：3 June 2010
• 年：2010
• 卷：584
• 期：11
• 页码：2415-2420
• 全文大小：718 K

文摘

The phosphatase calcineurin and the kinases Hal4/Hal5 regulate high-affinity potassium uptake in Saccharomyces cerevisiae through the Trk1 transporter. We demonstrate that calcineurin is necessary for high-affinity potassium uptake even in the absence of Na⁺ stress. HAL5 expression is induced in response to stress in a calcineurin–dependent manner through a newly identified functional CDRE (nt −195/−189). Lack of calcineurin decreases Hal5 protein levels, although with little effect on Trk1 amounts. However, the growth defect of cnb1 cells at K⁺-limiting conditions can be rescued in part by overexpression of HAL5, and this mutation further aggravates the potassium requirements of a hal4 strain. This suggests that the control exerted by calcineurin on Hal5 expression may be biologically relevant for Trk1 regulation.