Seyedin S M, Segarini P R, Rosen D M, Thompson A Y, Bentz H, Graycar J
J Biol Chem. 1987 Feb 15;262(5):1946-9.
Cartilage-inducing factors-A (CIF-A) and -B (CIF-B), purified from bovine bone on the basis of their ability to induce the cartilage phenotype in vitro, are proteins with molecular weights of 26,000 composed of two apparently identical disulfide-linked chains. CIF-A is apparently identical to TGF-beta from human platelets (Seyedin S. M., Thompson, A. Y., Bentz, H., Rosen, D. M., McPherson, J. M., Conti, A., Siegel, N. R., Galluppi, G. R., and Piez, K. A. (1986) J. Biol. Chem. 261, 5693-5695). We have now found that, like CIF-A and TGF-beta, CIF-B induces anchorage-independent proliferation of NRK-49F cells when these cells are simultaneously treated with epidermal growth factor. Furthermore, CIF-B competes with CIF-A for the same cell membrane receptors in NRK-49F cells. Partial amino acid sequencing reveals that CIF-B is a distinct molecule with extensive homology to CIF-A/TGF-beta. These results show that CIF-B and TGF-beta are structurally and functionally similar molecules, but differ more from each other than does TGF-beta from different species.
软骨诱导因子-A（CIF-A）和 -B（CIF-B）是从牛骨中纯化得到的，基于它们在体外诱导软骨表型的能力，它们是分子量为26,000的蛋白质，由两条明显相同的二硫键连接的链组成。CIF-A显然与人血小板中的转化生长因子-β（TGF-β）相同（赛耶丁·S.M.、汤普森·A.Y.、本茨·H.、罗森·D.M.、麦克弗森·J.M.、孔蒂·A.、西格尔·N.R.、加卢皮·G.R.和皮兹·K.A.（1986年）《生物化学杂志》261卷，5693 - 5695页）。我们现在发现，与CIF-A和TGF-β一样，当NRK - 49F细胞同时用表皮生长因子处理时，CIF-B会诱导这些细胞的不依赖贴壁的增殖。此外，CIF-B与CIF-A竞争NRK - 49F细胞中的相同细胞膜受体。部分氨基酸测序表明，CIF-B是一个与CIF-A/TGF-β具有广泛同源性的独特分子。这些结果表明，CIF-B和TGF-β是结构和功能相似的分子，但彼此之间的差异比不同物种的TGF-β之间的差异更大。
