CHARACTERIZATION OF A GROWTH-FACTOR THAT BINDS EXCLUSIVELY TO THE ERBB-2 RECEPTOR AND INDUCES CELLULAR-RESPONSES
CHARACTERIZATION OF A GROWTH-FACTOR THAT BINDS EXCLUSIVELY TO THE ERBB-2 RECEPTOR AND INDUCES CELLULAR-RESPONSES
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DOI：
10.1073/pnas.89.6.2287
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发表时间：
1992-03-15
影响因子：
11.1
通讯作者：
LIPPMAN, ME
中科院分区：
文献类型：
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作者：
LUPU, R;COLOMER, R;LIPPMAN, ME
erbB-2癌基因编码一种185 kDa的跨膜蛋白，被认为是一种生长因子受体。我们以前已经确定并纯化了一个30 kDa的生长因子（gp 30），这是一个配体的p185 erbB-2蛋白，在高浓度下诱导细胞的生长抑制与erbB-2扩增。我们现在报告从SKBr-3人乳腺癌细胞中纯化和鉴定分子量为75 kDa（p75）的蛋白质，该蛋白质是p185 erbB-2配体。使用与p185 erbB-2的胞外结构域偶联的亲和柱进行纯化。我们发现，p75诱导的erbB-2癌蛋白的酪氨酸磷酸化，在体内和体外磷酸化和磷酸氨基酸分析确定。p75以及gp 30刺激过表达erbB-2的细胞的细胞增殖和集落形成。通过显示可溶性erbB-2细胞外结构域的抗增殖作用被p75或gp 30逆转，证实了这种作用的特异性。p75没有显示与表皮生长因子受体结合，并且对过表达表皮生长因子受体的细胞没有生长作用。这些数据表明，SKBR-3细胞，表现出erbB-2扩增和过表达，分泌的生长因子，结合和激活p185 rbB-2特异性。
The erbB-2 oncogene encodes a 185-kDa transmembrane protein that has been suggested to be a growth factor receptor. We have previously identified and purified a 30-kDa growth factor (gp30) that is a ligand for the p185erbB-2 protein that at high concentrations induces growth inhibition of cells with erbB-2 amplification. We now report the purification and characterization of a protein from SKBr-3 human breast cancer cells with a molecular mass of 75 kDa (p75) that is a p185erbB-2 ligand. An affinity column coupled to the extracellular domain of p185erbB-2 was used for the purification. We found that p75 induced tyrosine phosphorylation of the erbB-2 oncoprotein, as determined by in vivo and in vitro phosphorylation and phosphoamino acid analysis. p75, as well as gp30, stimulated cell proliferation and colony formation of cells overexpressing erbB-2. The specificity of this effect was confirmed by showing that the antiproliferative effects of soluble erbB-2 extracellular domain were reversed by either p75 or gp30. p75 did not show binding to the epidermal growth factor receptor and had no growth effects on cells overexpressing epidermal growth factor receptor. These data show that SKBR-3 cells, which exhibit erbB-2 amplification and overexpression, secrete a growth factor that binds and activates p185rbB-2 specifically.