Functional Insights Into Protein Acetylation in the Hyperthermophilic Archaeon Sulfolobus islandicus
Functional Insights Into Protein Acetylation in the Hyperthermophilic Archaeon Sulfolobus islandicus
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超嗜热古菌岛硫化叶菌中蛋白质乙酰化的功能见解
DOI：
10.1074/mcp.ra119.001312
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发表时间：
2019-08-01
影响因子：
7
通讯作者：
Huang, Li
中科院分区：
文献类型：
--
作者：
Cao, Jingjing;Wang, Tongkun;Huang, Li
约26%的总蛋白质和44%的蛋白质被乙酰化的赖氨酸残基和N末端，分别在极端嗜热古菌硫化叶菌islandicus。Pat同源物优先乙酰化乙酰化蛋白质中的酰基辅酶A合成酶，而Ard 1同源物表现出广泛的底物特异性。色葡萄缺少Pat同源物的islandicus突变株没有显示出显著的生长缺陷，缺少Ard 1同源物的突变株比亲本株生长更慢。与细菌和真核生物一样，在酵母中，蛋白质在赖氨酸残基的N ε-氨基和N末端的N α-氨基上进行乙酰化。然而，在Escherichia的修改的程度，模式和作用仍然知之甚少。在这里，我们报告的野生型硫化叶菌islandicus菌株及其突变衍生菌株缺乏蛋白质乙酰转移酶Pat（三角洲SisPat）或NT-乙酰转移酶Ard 1（三角洲SisArd 1）的同源物的蛋白质组学分析。在684个蛋白质中发现了1708个N ε-乙酰化赖氨酸残基（占总蛋白质的26%），158个N t-乙酰化蛋白质（占已鉴定蛋白质的44%）。冰岛人。Delta SisArd 1的生长速度比亲本菌株慢，而Delta SisPat没有显示出明显的生长缺陷。1503个可定量的N ε-乙酰化赖氨酸残基中只有24个是差异乙酰化的，并且除了一个之外，所有24个残基在Delta SisPat中的乙酰化程度都比亲本菌株低>1.3倍，表明该酶的底物特异性窄。六个酰基辅酶A合成酶是SisPat在体内的优选底物，表明乙酰转移酶的N ε-乙酰化参与维持细胞中的代谢平衡。乙酰化酰基辅酶A合成酶的SisPat发生在一个序列基序保守的所有三个领域的生活。另一方面，92%的乙酰化的N末端被乙酰化的SisArd 1在细胞中。该酶具有广泛的底物特异性，可以修饰几乎所有类型的人NatA-NatF的目标N末端。SisArd 1基因的缺失使18%的可定量蛋白质（1518）的细胞水平改变>1.5倍。与Delta SisArd 1的生长表型一致，突变体中参与细胞分裂和细胞周期控制、DNA复制和嘌呤合成的蛋白质的细胞水平比亲本菌株中的蛋白质水平显著降低。
About 26% of the total proteins and 44% of the identified proteins were acetylated at lysine residues and the N terminus, respectively, in the hyperthermophilic archaeon Sulfolobus islandicus. A Pat homolog preferentially acetylated a group of acyl-CoA synthetases among the acetylated proteins, whereas an Ard1 homolog exhibited broad substrate specificity. A S. islandicus mutant strain lacking the Pat homolog showed no significant growth defects and that lacking the Ard1 homolog grew more slowly than the parent strain. Proteins undergo acetylation at the N epsilon-amino group of lysine residues and the N alpha-amino group of the N terminus in Archaea as in Bacteria and Eukarya. However, the extent, pattern and roles of the modifications in Archaea remain poorly understood. Here we report the proteomic analyses of a wild-type Sulfolobus islandicus strain and its mutant derivative strains lacking either a homolog of the protein acetyltransferase Pat (Delta SisPat) or a homolog of the Nt-acetyltransferase Ard1 (Delta SisArd1). A total of 1708 N epsilon-acetylated lysine residues in 684 proteins (26% of the total proteins), and 158 Nt-acetylated proteins (44% of the identified proteins) were found in S. islandicus. Delta SisArd1 grew more slowly than the parental strain, whereas Delta SisPat showed no significant growth defects. Only 24 out of the 1503 quantifiable N epsilon-acetylated lysine residues were differentially acetylated, and all but one of the 24 residues were less acetylated by >1.3 fold in Delta SisPat than in the parental strain, indicating the narrow substrate specificity of the enzyme. Six acyl-CoA synthetases were the preferred substrates of SisPat in vivo, suggesting that N epsilon-acetylation by the acetyltransferase is involved in maintaining metabolic balance in the cell. Acetylation of acyl-CoA synthetases by SisPat occurred at a sequence motif conserved among all three domains of life. On the other hand, 92% of the acetylated N termini identified were acetylated by SisArd1 in the cell. The enzyme exhibited broad substrate specificity and could modify nearly all types of the target N termini of human NatA-NatF. The deletion of the SisArd1 gene altered the cellular levels of 18% of the quantifiable proteins (1518) by >1.5 fold. Consistent with the growth phenotype of Delta SisArd1, the cellular levels of proteins involved in cell division and cell cycle control, DNA replication, and purine synthesis were significantly lowered in the mutant than those in the parental strain.