Backhaus Katja, Rippert Dorthe, Heilmann Clemens J, Sorgo Alice G, de Koster Chris G, Klis Frans M, Rodicio Rosaura, Heinisch Jürgen J
Universität Osnabrück, Fachbereich Biologie/Chemie, AG Genetik, Barbarastr. 11, D-49076 Osnabrück, Germany.
Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands.
Eur J Cell Biol. 2013 Dec;92(12):383-95. doi: 10.1016/j.ejcb.2014.01.001. Epub 2014 Jan 10.
The trimeric SNF1 complex from Saccharomyces cerevisiae, a homolog of mammalian AMP-activated kinase, has been primarily implicated in signaling for the utilization of alternative carbon sources to glucose. We here find that snf1 deletion mutants are hypersensitive to different cell wall stresses, such as the presence of Calcofluor white, Congo red, Zymolyase or the glucan synthase inhibitor Caspofungin in the growth medium. They also have a thinner cell wall. Caspofungin treatment triggers the phosphorylation of the catalytic Snf1 kinase subunit at Thr210 and removal of this phosphorylation site by mutagenesis (Snf1-T210A) abolishes the function of Snf1 in cell wall integrity. Deletion of the PFK1 gene encoding the α-subunit of the heterooctameric yeast phosphofructokinase suppresses the cell wall phenotypes of a snf1 deletion, which suggests a compensatory effect of central carbohydrate metabolism. Epistasis analyses with mutants in cell wall integrity (CWI) signaling confirm that the SNF1 complex and the CWI pathway independently affect yeast cell integrity.
来自酿酒酵母的三聚体SNF1复合物是哺乳动物AMP激活激酶的同源物,主要参与替代碳源用于葡萄糖代谢的信号传导。我们在此发现,snf1缺失突变体对不同的细胞壁应激高度敏感,例如生长培养基中存在荧光增白剂、刚果红、溶菌酶或葡聚糖合酶抑制剂卡泊芬净。它们的细胞壁也更薄。卡泊芬净处理会触发催化性Snf1激酶亚基在苏氨酸210处的磷酸化,通过诱变去除该磷酸化位点(Snf1-T210A)会消除Snf1在细胞壁完整性中的功能。编码异源八聚体酵母磷酸果糖激酶α亚基的PFK1基因的缺失抑制了snf1缺失的细胞壁表型,这表明中心碳水化合物代谢具有补偿作用。对细胞壁完整性(CWI)信号传导突变体的上位性分析证实,SNF1复合物和CWI途径独立影响酵母细胞的完整性。