Ahmadpour Doryaneh, Maciaszczyk-Dziubinska Ewa, Babazadeh Roja, Dahal Sita, Migocka Magdalena, Andersson Mikael, Wysocki Robert, Tamás Markus J, Hohmann Stefan
Department of Chemistry and Molecular Biology, University of Gothenburg, Sweden.
Institute of Experimental Biology, University of Wroclaw, Poland.
FEBS Lett. 2016 Oct;590(20):3649-3659. doi: 10.1002/1873-3468.12390. Epub 2016 Sep 28.
Arsenite is widely present in nature; therefore, cells have evolved mechanisms to prevent arsenite influx and promote efflux. In yeast (Saccharomyces cerevisiae), the aquaglyceroporin Fps1 mediates arsenite influx and efflux. The mitogen-activated protein kinase (MAPK) Hog1 has previously been shown to restrict arsenite influx through Fps1. In this study, we show that another MAPK, Slt2, is transiently phosphorylated in response to arsenite influx. Our findings indicate that the protein kinase activity of Slt2 is required for its role in arsenite tolerance. While Hog1 prevents arsenite influx via phosphorylation of T231 at the N-terminal domain of Fps1, Slt2 promotes arsenite efflux through phosphorylation of S537 at the C terminus. Our data suggest that Slt2 physically interacts with Fps1 and that this interaction depends on phosphorylation of S537. We hypothesize that Hog1 and Slt2 may affect each other's binding to Fps1, thereby controlling the opening and closing of the channel.
亚砷酸盐在自然界中广泛存在；因此，细胞已经进化出防止亚砷酸盐流入并促进其流出的机制。在酵母（酿酒酵母）中，水甘油通道蛋白Fps1介导亚砷酸盐的流入和流出。有丝分裂原激活蛋白激酶（MAPK）Hog1先前已被证明可通过Fps1限制亚砷酸盐的流入。在本研究中，我们发现另一种MAPK，即Slt2，会在亚砷酸盐流入时发生短暂磷酸化。我们的研究结果表明，Slt2的蛋白激酶活性是其在亚砷酸盐耐受性中发挥作用所必需的。虽然Hog1通过磷酸化Fps1 N端结构域的T231来防止亚砷酸盐流入，但Slt2通过磷酸化C端的S537来促进亚砷酸盐流出。我们的数据表明，Slt2与Fps1存在物理相互作用，且这种相互作用依赖于S537的磷酸化。我们推测，Hog1和Slt2可能会影响彼此与Fps1的结合，从而控制通道的开闭。
