Nuclear Transport of Granzyme B (Fragmentin-2)
Nuclear Transport of Granzyme B (Fragmentin-2)
复制标题
颗粒酶 B (Fragmentin-2) 的核运输
DOI：
--
复制
发表时间：
1996
影响因子：
4.8
通讯作者：
J. Trapani
中科院分区：
文献类型：
--
作者：
D. Jans;P. Jans;L. Briggs;V. Sutton;J. Trapani
细胞毒性 T 细胞和自然杀伤细胞能够通过成孔蛋白穿孔素和丝氨酸蛋白酶颗粒酶 B 的协同作用杀死其靶细胞，从而导致细胞凋亡典型的非常独特的核变化。穿孔素作用于细胞膜，而颗粒酶 B 似乎既能够进入靶细胞的细胞质，又能够在分离的细胞核中积累。在这项研究中，我们使用共聚焦激光扫描显微镜检查了荧光素化颗粒酶 B 在穿孔素存在下的体内完整细胞和体外半透化细胞中的核转运。观察到单独的颗粒酶 B 进入完整细胞的细胞质，但不积聚在细胞核中。然而，在穿孔素亚溶解浓度存在的情况下，其在完整细胞核中强烈积累，约2.5小时后最高水平约为细胞质中水平的1.5倍。体外核转运测定显示，颗粒酶 B 的核和核仁积累最大水平约为细胞质中积累的 2.5 倍和 3 倍。与体外 SV40 大肿瘤抗原 (T-Ag) 融合蛋白的信号依赖性核积累相反，颗粒酶 B 的核/核仁输入不依赖于 ATP，并且不会被不可水解的 GTP 类似物 GTPγS（鸟苷 5'-O-(3-硫代三磷酸））抑制。然而，与 T-Ag 融合蛋白类似，颗粒酶 B 的核和核仁积累依赖于外源添加的胞质。颗粒酶 B 蛋白酶活性的特异性抑制剂对核/核仁积累没有影响，这意味着蛋白水解活性对于核靶向不是必需的。结果表明，颗粒酶 B (32 kDa) 可能通过被动扩散从细胞质转运至细胞核，并在胞质因子介导的过程中通过与核/核仁因子结合而积累。在存在未标记的颗粒酶 B 的情况下，主动和被动核转运特性均正常，这意味着核膜和孔复合物不是颗粒酶 B 底物。
Cytotoxic T and natural killer cells are able to kill their target cells through synergistic action of the pore-forming protein perforin and the serine protease granzyme B, resulting in very distinctive nuclear changes typical of apoptosis. Whereas perforin acts at the membrane, granzyme B appears to be both capable of entering the cytoplasm of target cells and accumulating in isolated nuclei. In this study we examine nuclear transport of fluoresceinated granzyme B both in vivo in intact cells in the presence of perforin and in vitro in semi-permeabilized cells using confocal laser scanning microscopy. Granzyme B alone was observed to enter the cytoplasm of intact cells but did not accumulate in nuclei. In the presence of sublytic concentrations of perforin, however, it accumulated strongly in intact cell nuclei to levels maximally about 1.5 times those in the cytoplasm after about 2.5 h. In vitro nuclear transport assays showed maximal levels of nuclear and nucleolar accumulation of granzyme B of about 2.5- and 3-fold those in the cytoplasm. In contrast to signal-dependent nuclear accumulation of SV40 large tumor antigen (T-Ag) fusion proteins in vitro, nuclear/nucleolar import of granzyme B was independent of ATP and not inhibitable by the non-hydrolyzable GTP analog GTPγS (guanosine 5′-O-(3-thiotriphosphate)). Similar to T-Ag fusion proteins, however, granzyme B nuclear and nucleolar accumulation was dependent on exogenously added cytosol. Specific inhibitors of granzyme B protease activity had no effect on nuclear/nucleolar accumulation, implying that proteolytic activity was not essential for nuclear targeting. The results imply that granzyme B (32 kDa) may be transported from the cytoplasm to the nucleus through passive diffusion and accumulate by binding to nuclear/nucleolar factors in a cytosolic factor-mediated process. Active and passive nuclear transport properties were normal in the presence of unlabeled granzyme B, implying that the nuclear envelope and pore complex are not granzyme B substrates.
登录
查看更多内容
影响因子：
56.9
作者：
SCHINDLER, C;SHUAI, K;DARNELL, JE
通讯作者：
DARNELL, JE
颗粒酶 A 与靶细胞蛋白结合。
DOI：
--
发表时间：
1991
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Pasternack,MS;Bleier,KJ;McInerney,TN
通讯作者：
McInerney,TN
体内生长激素处理后核蛋白酪氨酸磷酸化的快速变化。
DOI：
--
发表时间：
1994
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Gronowski,AM;Rotwein,P
通讯作者：
Rotwein,P
影响因子：
2.9
作者：
GILL, SC;VONHIPPEL, PH
通讯作者：
VONHIPPEL, PH
哺乳动物核蛋白的氨基末端特异性识别 SV40 T 抗原型核定位序列。
影响因子：
6.6
作者：
Xue,Z;Shan,X;Lapeyre,B;Melese,T
通讯作者：
Melese,T