Protein tyrosine phosphorylation in signalling pathways leading to the activation of gelatinase A: activation of gelatinase A by treatment with the protein tyrosine phosphatase inhibitor sodium orthovanadate.
Protein tyrosine phosphorylation in signalling pathways leading to the activation of gelatinase A: activation of gelatinase A by treatment with the protein tyrosine phosphatase inhibitor sodium orthovanadate.
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信号通路中的蛋白酪氨酸磷酸化导致明胶酶 A 激活：用蛋白酪氨酸磷酸酶抑制剂原钒酸钠处理可激活明胶酶 A。
DOI：
10.1016/s0167-4889(98)00091-3
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
Seltzer,JL
中科院分区：
文献类型：
--
作者：
Li,L;Eisen,AZ;Sturman,E;Seltzer,JL
单层培养中的成纤维细胞仅以其酶原形式分泌明胶酶A（MMP 2; 72 kDa IV型胶原酶）。与其他分泌型基质金属蛋白酶不同，明胶酶A不易被丝氨酸蛋白酶激活。不同的代理商，包括莫能菌素，细胞松弛素D，和伴刀豆球蛋白A，已被发现介导的成纤维细胞单层分泌的明胶酶A酶原的激活。我们发现莫能菌素介导的活化可以被蛋白酪氨酸激酶抑制剂染料木黄酮逆转（Li et al.，Experimental Cell Research 232（1997）332）促使我们研究蛋白酪氨酸磷酸酶的特异性抑制剂原钒酸钠对明胶酶A活化的影响。用原钒酸盐处理成纤维细胞单层也会导致活性明胶酶A的分泌。这种激活是剂量和时间依赖性的，需要蛋白质合成，并与细胞膜相关。钒酸盐介导的活化在除莠霉素A（一种蛋白酪氨酸激酶抑制剂）存在下不发生。与莫能菌素、伴刀豆球蛋白A和细胞松弛素D介导的明胶酶活化一样，原钒酸盐处理导致膜蛋白酶MT 1-MMP的合成增加，其可以催化明胶酶A的活化。RT-PCR和北方杂交结果显示，蛋白酪氨酸激酶抑制剂能抑制MT 1-MMP mRNA的表达。此外，原钒酸盐增强莫能菌素和伴刀豆球蛋白A的作用。虽然用莫能菌素或伴刀豆球蛋白A治疗仅导致推定的激活剂MT 1-MMP的增加，但原钒酸盐还减少特异性抑制剂TIMP-2的产生。这些实验表明，蛋白酪氨酸磷酸化参与了信号转导途径，从而导致β-弹性蛋白酶A的活化。
Fibroblasts in monolayer culture secrete gelatinase A (MMP2; 72 kDa type IV collagenase) only in its proenzyme form. Unlike other secreted matrix metalloproteinases, progelatinase A is refractory to activation by serine proteinases. Disparate agents, including monensin, cytochalasin D, and concanavalin A, have been found to mediate the activation of gelatinase A zymogen secreted by fibroblast monolayers. Our finding that monensin-mediated activation can be reversed by the protein tyrosine kinase inhibitor genistein (Li et al., Experimental Cell Research 232 (1997) 332) prompted us to investigate the effect of the specific inhibitor of protein tyrosine phosphatases, sodium orthovanadate, on progelatinase A activation. Treatment of fibroblast monolayers with orthovanadate also results in the secretion of activated gelatinase A. This activation is dose- and time-dependent, requires protein synthesis, and is associated with cell membranes. Vanadate-mediated activation does not occur in the presence of herbimycin A, a protein tyrosine kinase inhibitor. As with progelatinase activation mediated by monensin, concanavalin A, and cytochalasin D, orthovanadate treatment results in increased synthesis of the membrane proteinase MT1-MMP, that can catalyze the activation of progelatinase A. Protein tyrosine kinase inhibitors are able to prevent the increase of MT1-MMP mRNA, as shown by Northern blot and RT-PCR. In addition, orthovanadate potentiates the effects of monensin and concanavalin A. While treatment with monensin or concanavalin A result only in an increase of the putative activator MT1-MMP, orthovanadate also reduces the production of the specific inhibitor TIMP-2. These experiments implicate protein tyrosine phosphorylation in the signal transduction pathways which lead to the activation of progelatinase A.