Mouse fibroblasts defective in thrombin mitogenesis possess functional proteolytically activated receptor for thrombin: requirement for a second signaling pathway.
Mouse fibroblasts defective in thrombin mitogenesis possess functional proteolytically activated receptor for thrombin: requirement for a second signaling pathway.
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凝血酶有丝分裂发生缺陷的小鼠成纤维细胞具有功能性蛋白水解激活凝血酶受体：需要第二条信号通路。
DOI：
10.1002/jcp.1041600321
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发表时间：
1994
影响因子：
5.6
通讯作者：
Carney,DH
中科院分区：
文献类型：
--
作者：
Kim,DW;Wang,F;Ramakrishnan,S;Scott,DL;Hensler,TM;Thompson,WC;Carney,DH
成纤维细胞的凝血酶有丝分裂需要两个不同的信号亚群；一个由蛋白水解性裂解产生，另一个由高亲和力细胞表面结合产生。我们对两个具有大量凝血酶结合位点的亲缘关系密切的小鼠胚胎(ME)细胞株进行了鉴定，发现其中一株系B11-A对凝血酶、表皮生长因子(EGF)和血清有丝分裂反应，而B11-B细胞系对EGF和血清有反应，但对凝血酶不反应。导致凝血酶反应性丧失的B11-B缺陷不是由于高亲和力结合位点的数量的差异，也不是由于凝血酶与这些结合位点的亲和力的差异，也不是由于蛋白水解性激活的凝血酶受体(部分)的细胞表面表达的差异。该缺陷也与凝血酶不能激活部分无关，因为凝血酶刺激B11-A和B11-B细胞的原癌基因c-fosin的切割依赖的诱导。凝血酶、人工合成的凝血酶受体多肽、Trp-14(SFFLRNPGENTFEL)、血小板衍生生长因子(PDGF)和佛波酯(PMA)的不同组合被用来更好地确定凝血酶介导的B11-B细胞有丝分裂的缺陷。用PMA联合凝血酶直接激活蛋白激酶C并不能克服B11-B无反应性。然而，通过同时加入PDGF和凝血酶或Trp-14，B11-B细胞重新获得了丝裂原反应性。因此，B11-B缺陷可能涉及一组由非蛋白水解性凝血酶相互作用启动的信号，不同于部分启动的信号，但与酪氨酸激酶相关生长因子EGF和PDGF启动的下游信号有关。©1994 Wiley-Liss，Inc.
Thrombin mitogenesis in fibroblasts requires two distinguishable subsets of signals; one generated by proteolytic cleavage, the other by high‐affinity cell surface binding. Characterizing two closely related mouse embryo (ME) cell lines with high numbers of thrombin binding sites, we found that one line, B11‐A, responds mitogenically to thrombin, epidermal growth factor (EGF), and serum, whereas the B11‐B cell line is responsive to EGF and serum, but not to thrombin. The B11‐B defect responsible for loss of thrombin responsiveness is not due to differences in the number of high‐affinity binding sites, the affinity of thrombin binding to these sites, or to differences in cell surface expression of proteolytically activated receptors for thrombin (PART). The defect is also not associated with an inability of thrombin to activate PART since thrombin stimulates the cleavage‐dependent induction of the proto‐oncogene c‐fosin both B11‐A and B11‐B cells. Various combinations of thrombin, synthetic thrombin receptor peptide, TRP‐14 (SFFLRNPGENTFEL), platelet‐derived growth factor (PDGF), and phorbol 12‐myristate 13‐acetate (PMA) were used to better define the defect in thrombin‐mediated mitogenesis in B11‐B cells. Direct activation of protein kinase C with PMA in combination with thrombin did not overcome B11‐B nonresponsiveness. However, mitogenic responsiveness was regained in B11‐B cells by simultaneous addition of PDGF and either thrombin or TRP‐14. Therefore, the B11‐B defect may involve a set of signals initiated by nonproteolytic thrombin interactions distinct from those initiated by PART, but related to the downstream signals initiated by the tyrosine kinase‐associated growth factors, EGF and PDGF. © 1994 Wiley‐Liss, Inc.