INTRODUCTION Placental form glutathione S-transferase(GST-pi)isa group of isoenzymes with protein combiningability.Since the reports showing that GST-pi wassignificantly increased in proliferative hepaticnodule induce...INTRODUCTION Placental form glutathione S-transferase(GST-pi)isa group of isoenzymes with protein combiningability.Since the reports showing that GST-pi wassignificantly increased in proliferative hepaticnodule induced by chemical carcinogen and in welldifferentiated carcinoma,more studies haveshown that GST-pi expressed highly inneoplasm,and could be regarded as a展开更多
谷胱甘肽S-转移酶(glutathione S-transferases,GSTs)是细胞内降解生物异源物质(xenbiotics)的一类酶,GSTπ/GSTpi/GSTp是人体内的一种重要活性亚型;有丝分裂原激活的蛋白激酶(mitogen-activated protein kinase,MAPK)途径能够调节真核...谷胱甘肽S-转移酶(glutathione S-transferases,GSTs)是细胞内降解生物异源物质(xenbiotics)的一类酶,GSTπ/GSTpi/GSTp是人体内的一种重要活性亚型;有丝分裂原激活的蛋白激酶(mitogen-activated protein kinase,MAPK)途径能够调节真核细胞凋亡、增殖、分化和应激。1999年国际上首次报道GSTpi能够在MAPK信号途径中起调节作用,其作用机制如下:在正常生长条件下,GSTpi以单体形式与JNK(c-Jun N-terminal kinase)形成复合物,抑制JNK活性;UV照射或H_2O_2处理细胞后,GSTpi自身形成二聚体/多聚体,导致GSTpi-JNK复合物解离,JNK的抑制被解除,JNK被磷酸化激活后激活转录因子c-Jun,c-Jun的激活能进一步促进GSTpi基因的转录,进而合成新的GSTpi蛋白单体,该单体又能反馈抑制JNK。后续研究发现GSTpi也能够抑制JNK激酶的上游激酶ASK1的活性。上述研究揭示GSTpi酶在细胞内除能通过降低异源物质而改变细胞的ROS平衡外,其蛋白本身还具有特异性地抑制MAPK信号转导途径中JNK激酶和JNK上游激酶的新功能。展开更多
文摘INTRODUCTION Placental form glutathione S-transferase(GST-pi)isa group of isoenzymes with protein combiningability.Since the reports showing that GST-pi wassignificantly increased in proliferative hepaticnodule induced by chemical carcinogen and in welldifferentiated carcinoma,more studies haveshown that GST-pi expressed highly inneoplasm,and could be regarded as a
