Synthesis, post-translational processing, and autocrine transforming activity of a carboxylterminal truncated form of colony stimulating factor-1.
Synthesis, post-translational processing, and autocrine transforming activity of a carboxylterminal truncated form of colony stimulating factor-1.
复制标题
DOI：
--
复制
发表时间：
1987-09
期刊：
影响因子：
--
通讯作者：
J. Heard;M. Roussel;C. W. Rettenmier;C. Sherr
中科院分区：
文献类型：
--
作者：
J. Heard;M. Roussel;C. W. Rettenmier;C. Sherr
由1.6千碱基对人cDNA编码的单核吞噬细胞集落刺激因子是一种同二聚体跨膜糖蛋白，通过蛋白水解从质膜释放出来。过早终止其羧基端跨膜段上游的CSF-1编码序列，并在牛乳头瘤病毒或逆转录病毒载体中表达截断的CSF-1 cDNA，可合成一种可溶性的、生物活性的生长因子，该生长因子可迅速从细胞中分泌出来。与全长CSF-1前体一样，截断的多肽在合成后立即通过二硫键快速组装，并获得与天冬酰胺相连的低聚糖链，在细胞内运输过程中经历了逐步的翻译后修饰。截断cDNA编码的可溶性CSF-1与人c-fms原癌基因产物（CSF-1受体）共表达时，可在半固体培养基中刺激骨髓源性小鼠巨噬细胞菌落的形成，诱导小鼠NIH-3T3细胞的转化。与全长CSF-1 cDNA获得的结果相比，截断的CSF-1基因获得的转化效率降低了，尽管转染的培养物产生了相似水平的细胞外生长因子。结果表明，CSF-1氨基酸残基1-158（连同残基-32至-1的氨基末端信号肽）足以维持生物活性，并且编码膜结合或可溶性前体的CSF-1 cdna在自分泌转化中具有活性。
The mononuclear phagocyte colony stimulating factor encoded by a 1.6 kilobase pair human cDNA is synthesized as a homodimeric transmembrane glycoprotein that is released from the plasma membrane by proteolysis. Premature termination of the CSF-1 coding sequence upstream of its carboxylterminal transmembrane-spanning segment and expression of the truncated CSF-1 cDNA in either bovine papilloma virus or retrovirus vectors led to the synthesis of a soluble, biologically active growth factor that was rapidly secreted from cells. Like the full-length CSF-1 precursor, the truncated polypeptide was rapidly assembled through disulfide bonds immediately after synthesis and acquired asparagine-linked oligosaccharide chains that underwent progressive post-translational modifications during intracellular transport. Soluble CSF-1 encoded by the truncated cDNA stimulated the formation of bone marrow-derived mouse macrophage colonies in semisolid medium and induced transformation of mouse NIH-3T3 cells when coexpressed with the human c-fms proto-oncogene product (CSF-1 receptor). Compared to results obtained with the full-length CSF-1 cDNA, the efficiency of transformation obtained with the truncated CSF-1 gene was reduced, in spite of the fact that transfected cultures produced similar levels of the extracellular growth factor. The results indicate that CSF-1 amino acid residues 1-158 (together with the aminoterminal signal peptide at residues -32 to -1) are sufficient for biological activity and that CSF-1 cDNAs encoding either membrane-bound or soluble precursors are active in autocrine transformation.