Analysis of phosphorylated sphingolipid long-chain bases reveals potential roles in heat stress and growth control in Saccharomyces
Analysis of phosphorylated sphingolipid long-chain bases reveals potential roles in heat stress and growth control in Saccharomyces
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DOI：
10.1128/jb.181.4.1134-1140.1999
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发表时间：
1999-02-01
影响因子：
3.2
通讯作者：
Dickson, RC
中科院分区：
文献类型：
--
作者：
Skrzypek, MS;Nagiec, MM;Dickson, RC
鞘脂长链碱基及其磷酸化衍生物，例如哺乳动物的鞘鞘醇-磷酸，已被认为是信号分子。酿酒酵母细胞也使用长链碱基磷酸盐调节细胞过程的可能性最近才开始被研究。在这里，我们提出了一种简单而敏感的方法来分析和定量酿酒酵母细胞中的长链碱基磷酸盐。我们的数据首次表明，植鞘鞘醇-1-磷酸（PHS-1-P）在25℃可发酵碳源上生长的细胞中以低但可检测的水平存在，而二氢鞘鞘醇-1-磷酸（DHS-1-P）仅勉强可检测到。将细胞温度调至37℃时，ph -1- p和DHS-1-P的含量分别瞬时增加8倍和5倍，并在大约10分钟后达到峰值，两种化合物的含量在温度调至37℃后20分钟恢复到非应激水平。这些数据与PHS-1-P和DHS-1-P是信号分子一致。由于DPL1和LCB3的缺失，不能分解长链碱基磷酸盐的细胞显示出ph -1- p和DHS-1-P水平增加500倍，生长缓慢，在44℃热应激下的存活率比亲本细胞高10倍。dpl1或lcb3单突变菌株的这些数据和其他数据表明，DHS-1-P和/或PHS-1-P是耐热性的信号。我们的方法应该加快实验，以确定这些化合物的合成和分解是如何被调节的，以及这些化合物是如何介导对高温的抗性的。
Sphingolipid long-chain bases and their phosphorylated derivatives, for example, sphingosine-l-phosphate in mammals, have been implicated as signaling molecules. The possibility that Saccharomyces cerevisiae cells also use long-chain-base phosphates to regulate cellular processes has only recently begun to be examined, Here we present a simple and sensitive procedure for analyzing and quantifying long-chain-base phosphates in S. cerevisiae cells. Our data show for the first time that phytosphingosine-1-phosphate (PHS-1-P) is present at a low but detectable level in cells grown on a fermentable carbon source at 25 degrees C, while dihydrosphingosine-1-phosphate (DHS-1-P) is only barely detectable. Shifting cells to 37 degrees C causes transient eight- and fivefold increases in levels of PHS-1-P and DHS-1-P, respectively, which peak after about 10 min, The amounts of both compounds return to the unstressed levels by 20 min after the temperature shift. These data are consistent with PHS-1-P and DHS-1-P being signaling molecules. Cells unable to break down long-chain-base phosphates, due to deletion of DPL1 and LCB3, show a 500-fold increase in PHS-1-P and DHS-1-P levels, grow slowly, and survive a 44 degrees C heat stress 10-fold better than parental cells. These and other data for dpl1 or lcb3 single-mutant strains suggest that DHS-1-P and/or PHS-1-P act as signals for resistance to heat stress, Our procedure should expedite experiments to determine how the synthesis and breakdown of these compounds is regulated and how the compounds mediate resistance to elevated temperature.