【作者】 王振辉； 邵铱娜； 李成华； 吕志猛； 王海宏； 张卫卫； 赵雪琳；

【Author】 Zhenhui Wang;Yina Shao;Chenghua Li;Zhimeng Lv;Haihong Wang;Weiwei Zhang;Xuelin Zhao;School of Marine Sciences, Ningbo University;

【机构】 海洋学院宁波大学；

【摘要】 整合素属于膜上糖蛋白,主要作为细胞外基质和细胞与细胞之间黏附性分子的受体。在本实验中,我们克隆获取了全长为1038bp的仿刺参的一种新型整合素β亚基的基因,该基因的氨基酸序列具有与近源物种保守的胞外三肽(精氨酸-甘氨酸-天冬氨酸,RGD)结合结构域,跨膜结构域和胞内结构域三部分组成,其中RGD结合结构域具有典型的C31位S-diglycerid或者N-Palm半胱氨酸残基。定量PCR分析发现整合素广泛的分布于各个组织,最多在肌肉中,最少在呼吸树中。此外,我们还发现经病原菌灿烂弧菌和脂多糖胁迫仿刺参后整合素的信使RNA的表达量均发生了显著的上调。我们还发现整合素的重组蛋白具有较强的脂多糖结合活性,而对肽聚糖和甘露聚糖的结合能力稍差。我们通过对整合素的体外敲除实验发现敲除组的细胞凋亡率高于对照组,以上的结果表明了整合素可能在宿主与病原菌作用中通过发挥其脂多糖结合活性从而扮演了凋亡抑制子的角色。更多还原

【Abstract】 Integrins are a family of membrane glycoproteins, which are major receptors for extracellular matrix and cell-cell adhesion molecules. In this study, an 1038 bp sequence representing full length cDNA of a novel β subunit integrin was cloned from Apostichopus japonicus(designated as AjITGB). The deduced amino acid sequence of AjITGB shared an conserved RGD binding domain with a S-diglycerides cysteine or N-palm cysteine residue(C31), a transmembrane domain and a β-integrin cytoplasm domain. Spatial distribution analysis showed that AjITGB was constitutively expressed in all tested tissues with dominant expressed in muscles and weakly in respiratory tree. The pathogen Vibrio splenfidus challenge and LPS stimulation could both significantly down-regulate the mRNA expression of AjITGB. Functional investigation revealed that recombinant AjITGB(r AjITGB) displayed higher LPS binding activity and lower to PGN and MAN. More importantly, knock-down AjITGB by specific siRNA resulted in significant promotion for coelomocytes apoptosis in vitro.更多还原