Suppressors of the Ca(2+)-sensitive yeast mutant (csg2) identify genes involved in sphingolipid biosynthesis. Cloning and characterization of SCS1, a gene required for serine palmitoyltransferase activity.
Suppressors of the Ca(2+)-sensitive yeast mutant (csg2) identify genes involved in sphingolipid biosynthesis. Cloning and characterization of SCS1, a gene required for serine palmitoyltransferase activity.
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发表时间：
1994-08
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通讯作者：
C. Zhao;T. Beeler;T. Dunn
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作者：
C. Zhao;T. Beeler;T. Dunn
研究了酿酒酵母中阻断Ca（2+）诱导的csg 2突变细胞死亡的抑制突变。这些突变体被称为scs突变体（suppressor of Ca 2 + sensitivity），分为7个互补组（scs 1-scs 7）。两个互补组（scs 1和scs 2）中的所有突变株同时获得对10 mM Ca 2+的需求，而野生型仅在痕量Ca 2+下生长。通过补充其Ca（2+）-需要表型克隆了SCS 1，并发现其与催化酰基转移反应的磷酸吡哆醛酶家族同源。scs 1突变体的次级表型表明，SCS 1是丝氨酸棕榈酰转移酶活性所必需的，该活性催化鞘脂生物合成中的第一个关键步骤（棕榈酰-CoA+丝氨酸->3-酮鞘氨醇+CoASH+CO2）。其他scs突变体以及csg 2无效突变体改变了鞘脂代谢。这些数据表明，酵母中的鞘脂代谢是由Ca 2+调节和/或需要Ca 2+稳态。
Suppressor mutations in Saccharomyces cerevisiae that block Ca(2+)-induced death of csg2 mutant cells were investigated. These mutants, called scs mutants (suppressor of Ca2+ sensitivity), fall into seven complementation groups (scs1-scs7). All mutant strains in two of the complementation groups (scs1 and scs2) simultaneously acquire a requirement for 10 mM Ca2+, whereas wild type grow with only trace amounts of Ca2+. SCS1 was cloned by complementation of its Ca(2+)-requiring phenotype and found to be homologous to a family of pyridoxal phosphate enzymes that catalyze acyltransfer reactions. Secondary phenotypes of the scs1 mutants indicate that SCS1 is required for serine palmitoyltransferase activity which catalyzes the first committed step in sphingolipid biosynthesis (palmitoyl-CoA + serine-->3-ketosphinganine+CoASH+CO2). Other scs mutants as well as the csg2 null mutant have altered sphingolipid metabolism. The data suggest that sphingolipid metabolism in yeast is either regulated by Ca2+ and/or is required for Ca2+ homeostasis.