STIMULATION BY HEME OF STERYL ESTER SYNTHASE AND AEROBIC STEROL EXCLUSION IN THE YEAST SACCHAROMYCES-CEREVISIAE
STIMULATION BY HEME OF STERYL ESTER SYNTHASE AND AEROBIC STEROL EXCLUSION IN THE YEAST SACCHAROMYCES-CEREVISIAE
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DOI：
10.1016/0003-9861(92)90600-2
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发表时间：
1992-08-01
影响因子：
3.9
通讯作者：
PARKS, LW
中科院分区：
文献类型：
--
作者：
KEESLER, GA;CASEY, WM;PARKS, LW
酵母属植物的甾醇和血红素营养缺陷型被用来阐明血红素在甾醇酯化中的作用。在补充50 μg/ml δ-氨基乙酰丙酸（ALA）的细胞中，甾醇酯合成酶（SES）活性平均刺激4倍。这种刺激并不依赖于ALA本身，而是依赖于这种前体影响血红素能力的能力。ALA的加入刺激了酵母对发酵或呼吸碳源的SES活性。SES活性的升高与细胞内游离固醇、不饱和脂肪酸或甲硫氨酸水平无关。SES活性随着细胞进入稳定期而增加，并且这种增加通过血红素能力而增强。SES被降胆固醇药物洛伐他汀（mevinolin）直接抑制。洛伐他汀对血红素感受态细胞SES活性的抑制作用增强。
Saccharomyces cerevisiaesterol and heme auxotrophs were used to elucidate a role for hemes in sterol esterification. Steryl ester synthase (SES) activity was stimulated on average fourfold in cells supplemented with 50 μg/ml δ-aminolevulinic acid (ALA). This stimulation was not dependent on ALA per se, but on the ability of this precursor to effect heme competency. The addition of ALA stimulated SES activity of yeast on either fermentative or respiratory carbon sources. The elevation of SES activity was independent of intracellular free sterol, unsaturated fatty acid, or methionine levels. SES activity increases as the cells enter stationary phase, and this increase is enhanced by heme competency. SES was directly inhibited by the hypocholesterolemic drug lovastatin (mevinolin). The inhibition of SES activity by lovastatin was enhanced in heme-competent cells.