Sac1, a putative regulator that is critical for survival of Chlamydomonas reinhardtii during sulfur deprivation
Sac1, a putative regulator that is critical for survival of Chlamydomonas reinhardtii during sulfur deprivation
复制标题
DOI：
10.1002/j.1460-2075.1996.tb00568.x
复制
发表时间：
1996-05-01
期刊：
影响因子：
11.4
通讯作者：
Grossman, A
中科院分区：
文献类型：
--
作者：
Davies, JP;Yildiz, FH;Grossman, A
莱茵衣藻SAC1突变体在大多数正常的限硫反应中都存在异常；它不能合成芳基硫酸酯酶，不能像野生型细胞那样快速吸收硫酸盐，也不能合成在限硫生长过程中正常积累的周质蛋白。在这里，我们发现SAC1突变体在缺硫期间比野生型细胞更快死亡；这强调了驯化过程的重要作用，在缺硫期间，SAC1突变体的活性丧失只在光中观察到，并且大部分被DCMU抑制，在硫胁迫期间，野生型细胞，而不是SAC1突变体，下调光合作用，因此，SAC1突变体在缺硫期间的死亡可能是由于它不能下调光合作用的结果。此外，由于SAC1是光合作用下调所必需的，这一过程必须受到高度控制，而不是简单地由于硫限制导致蛋白质合成减少的结果。SAC1基因的基因组和cDNA拷贝已经被克隆，其推导的氨基酸序列与可能参与大肠杆菌对营养缺乏的反应的大肠杆菌基因相似。
The sac1 mutant of Chlamydomonas reinhardtii is aberrant in most of the normal responses to sulfur limitation; it cannot synthesize arylsulfatase, does not take up sulfate as rapidly as wild-type cells, and does not synthesize periplasmic proteins that normally accumulate during sulfur-limited growth, Here, we show that the sac1 mutant dies much more rapidly than wild-type cells during sulfur deprivation; this emphasizes the vital role of the acclimation process, The loss of viability of the sac1 mutant during sulfur deprivation is only observed in the light and is mostly inhibited by DCMU, During sulfur-stress, wild-type cells, but not the sac1 mutant, downregulate photosynthesis, Thus, death of the sac1 mutant during sulfur deprivation is probably a consequence of its inability to downregulate photosynthesis. Furthermore, since SAC1 is necessary for the downregulation of photosynthesis, the process must be highly controlled and not simply the result of a general decrease in protein synthesis due to sulfur limitation, Genomic and cDNA copies of the SAC1 gene have been cloned, The deduced amino acid sequence of Sac1 is similar to an Escherichia coli gene that may involved in the response of E.coli to nutrient deprivation.