炭疽毒素受体结构和功能研究进展

Progress in Structure and Function of Anthrax Toxin Receptors

肿瘤血管内皮标志物8(TEM8)和毛细血管形态发生蛋白2(CMG2)是已知的两个炭疽毒素受体,它们的主要功能是当炭疽杆菌侵染细胞时介导炭疽毒素进入宿主细胞。这两个受体都是涉及到细胞外基质动态平衡的I型跨膜蛋白,并且都因为它们在血管生成或血管内皮细胞中表达增强而被发现。有研究发现TEM8能够调节内皮细胞迁移和血管形成,而CMG2则在内皮细胞增殖过程中起重要作用。进一步的研究显示它们与整联蛋白同源性较高,但它们确切的生理功能和作用机制尚不明确。本文中,主要讨论这两种蛋白的结构和它们作为炭疽毒素受体介导炭疽毒素进入细胞的分子机制,然后我们简单探讨一下TEM8在靶向肿瘤血管内皮细胞的抗血管生成和抗肿瘤疗法方面的研究进展,最后我们展望了下一步炭疽毒素受体研究的热点-它们的配体及生理功能研究。

Tumor endothelial marker 8 （TEM8） and capillary morphogenesis protein 2 （CMG2） are the two anthrax toxin recep- tors, which function as mediating anthrax toxin entry into host ceils when Bacillus anthracis infected cells. These two receptors are the type I transmembrane proteins related to the dynamic equilibrium of the extracellular matrix, and they were originally identified as a gene upregulated during angiogenesis. Some studies had found that TEM8 was able to regulate endothelial cell migration and angiogenesis, while CMG2 played an important role in the process of endothelial cell proliferation. Further studies had shown that they shares interest- ing similarities with integrins, however their exact physiological function and mechanism is unclear. In this article, we mainly discuss the structures of these two proteins and their function and molecular mechanism as anthrax toxin receptor mediating anthrax toxin into cells, and then we briefly explore the progress of TEM8 in anti-angiogenesis and anti-tumor therapy research. Finally, we look forward to the next hotspot of the anthrax toxin receptors research.