Zhang J G, Zhang Y, Owczarek C M, Ward L D, Moritz R L, Simpson R J, Yasukawa K, Nicola N A
Cooperative Research Centre for Cellular Growth Factors and the Walter and Eliza Hall Institute of Medical Research, Post Office Royal Melbourne Hospital, Victoria 3050, Australia.
J Biol Chem. 1998 Apr 24;273(17):10798-805. doi: 10.1074/jbc.273.17.10798.
Leukemia inhibitory factor (LIF) is a polyfunctional cytokine known to require at least two distinct receptor components (LIF receptor alpha-chain and gp130) in order to form a high affinity, functional receptor complex. In this report, we present evidence that there are two distinct truncated forms of gp130 in normal human urine and plasma: a large form with a molecular weight of approximately 100, 000, which is similar to a previously described form of soluble gp130 in human serum, and a previously undescribed small form with a molecular weight of approximately 50,000. Using a panel of monoclonal antibodies raised against the extracellular domain of human gp130, we were able to show that the small form of the urinary gp130 probably contained only the hemopoietin domain. Both forms of gp130 bound LIF specifically and were capable of forming heterotrimeric complexes with soluble human LIF receptor alpha-chain in the presence of human LIF. In addition to the soluble forms of gp130, a soluble form of LIF receptor alpha-chain was also detected in human urine and plasma.
白血病抑制因子（LIF）是一种多功能细胞因子，已知其需要至少两种不同的受体成分（LIF受体α链和gp130）才能形成高亲和力的功能性受体复合物。在本报告中，我们提供证据表明，正常人尿液和血浆中存在两种不同的截短形式的gp130：一种分子量约为100,000的大形式，类似于先前描述的人血清中可溶性gp130的形式；以及一种先前未描述的分子量约为50,000的小形式。使用一组针对人gp130细胞外结构域产生的单克隆抗体，我们能够证明尿液中gp130的小形式可能仅包含造血素结构域。两种形式的gp130都能特异性结合LIF，并在人LIF存在的情况下能够与可溶性人LIF受体α链形成异源三聚体复合物。除了可溶性形式的gp130外，在人尿液和血浆中还检测到了可溶性形式的LIF受体α链。
