Processing of newly synthesized cachectin/tumor necrosis factor in endotoxin-stimulated macrophages.
Processing of newly synthesized cachectin/tumor necrosis factor in endotoxin-stimulated macrophages.
复制标题
内毒素刺激的巨噬细胞中新合成的恶病素/肿瘤坏死因子的加工。
DOI：
10.1021/bi00488a025
复制
发表时间：
1990
期刊：
影响因子：
2.9
通讯作者：
Cerami,A
中科院分区：
文献类型：
--
作者：
Jue,DM;Sherry,B;Luedke,C;Manogue,KR;Cerami,A
在小鼠巨噬细胞样细胞系RAW 264.7中检测了cachetin/肿瘤坏死因子（TNF）的生物合成和加工。脂多糖刺激的细胞分泌糖基化和非糖基化的17千道尔顿（kDa）的成熟恶病质/TNF到培养基中。分泌的恶病质/TNF来源于膜相关的前体，所述前体由针对79个氨基酸的恶病质/TNF激素原序列的成熟蛋白或合成肽片段的多克隆抗血清沉淀。大约一半的前体是N-糖基化的，显然是互补的。然后将恶液质/TNF前体蛋白水解裂解以将可溶性成熟细胞因子释放到培养基中，而膜结合的14-kDa前序列保持细胞缔合。在LPS刺激期间，巨噬细胞表面Cachectin/TNF的量保持在低水平，表明Cachectin/TNF的非糖基化和糖基化前体均被这些细胞有效地切割。这些发现表明存在一种独特的分泌恶病质/TNF的机制。
The biosynthesis and processing of cachetin/tumor necrosis factor (TNF) were examined in the murine macrophage-like cell line RAW 264.7. Lipopolysaccharide-stimulated cells secreted both glycosylated and nonglycosylated 17-kilodalton (kDa) mature cachectin/TNF into the culture medium. Secreted cachectin/TNF was derived from membrane-associated precursors that were precipitated by polyclonal antisera raised against either the mature protein or synthetic peptide fragments of the 79 amino acid cachectin/TNF prohormone sequence. About half of the precursors were N-glycosylated, apparently cotranslationally. The cachectin/TNF precursors were then proteolytically cleaved to release soluble mature cytokine into the medium, while the membrane-bound 14-kDa prosequence remained cell associated. During the period of LPS stimulation, the amount of macrophage cell surface cachectin/TNF remained at a low level, suggesting that both nonglycosylatedand glycosylated precursors of cachectin/TNF are efficiently cleaved by these cells. These findings suggest the presence of a unique mechanism for the secretion of cachectin/TNF.