Sequence and tissue distribution of the human integrin alpha 8 subunit: a beta 1-associated alpha subunit expressed in smooth muscle cells.
Sequence and tissue distribution of the human integrin alpha 8 subunit: a beta 1-associated alpha subunit expressed in smooth muscle cells.
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发表时间：
1995-02
影响因子：
4
通讯作者：
L. M. Schnapp;Johannes M. Breuss;Daniel M. Ramos;D. Sheppard;R. Pytela
中科院分区：
文献类型：
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作者：
L. M. Schnapp;Johannes M. Breuss;Daniel M. Ramos;D. Sheppard;R. Pytela
整合素是参与细胞-细胞和细胞-细胞外基质相互作用的细胞粘附分子的主要家族。每个整联蛋白是由α和β亚基组成的异二聚体糖蛋白。我们现在报告的cDNA序列和分布的一个新的人类整合素α亚基。该序列与先前报道的鸡α 8整联蛋白序列78%相同。因此，我们将这个亚基命名为人类α 8。通过北方印迹分析，α 8探针在神经胶质瘤H4细胞中检测到约6.5和4.0 kb的两种mRNA。抗α 8多克隆抗体沉淀出含有与推定α 8亚基相关的β 1亚基的蛋白复合物，其表观分子量为180 kDa（非还原）或155 kDa和25 kDa（还原）。成年大鼠组织中抗α 8多克隆抗体的免疫组织化学显示血管和内脏平滑肌中的显著染色。此外，抗体强烈染色肾系膜细胞和肺肺泡壁中的细胞类型，最可能对应于肺泡肌成纤维细胞。这些结果表明，在成年哺乳动物组织中，α 8主要在平滑肌和平滑肌样收缩细胞中表达。
Integrins are a major family of cell adhesion molecules involved in cell-cell and cell-extracellular matrix interactions. Each integrin is a heterodimeric glycoprotein composed of an alpha and a beta subunit. We now report the cDNA sequence and distribution of a new human integrin alpha subunit. This sequence is 78% identical to the previously reported chicken alpha 8 integrin sequence. Thus, we have designated this subunit as human alpha 8. By northern blot analysis, an alpha 8 probe detects two mRNA species of approximately 6.5 and 4.0 kb in neuroglioma H4 cells. An anti-alpha 8 polyclonal antibody precipitates a protein complex containing the beta 1 subunit associated with the putative alpha 8 subunit, which has an apparent molecular mass of 180 kDa (non-reduced) or 155 kDa and 25 kDa (reduced). Immunohistochemistry with anti-alpha 8 polyclonal antibody in adult rat tissues shows prominent staining in vascular and visceral smooth muscle. In addition, the antibody strongly stained kidney mesangial cells and a cell type in the alveolar wall of the lungs, most likely corresponding to alveolar myofibroblasts. These results suggest that in adult mammalian tissues, alpha 8 is predominantly expressed in smooth muscle and smooth muscle-like contractile cells.