Hill R M, Morresey K S, Coates L C, Mezey E, Fell B, Bratt T, Trapani J A, Birch N P
Molecular Neuroendocrinology Group, School of Biological Sciences, University of Auckland, New Zealand.
FEBS Lett. 1998 Dec 4;440(3):361-4. doi: 10.1016/s0014-5793(98)01475-6.
We have cloned a novel serpin (raPIT5a) from a rat pituitary cDNA library which is structurally related to members of the ovalbumin subfamily of serine protease inhibitors. This new cDNA encodes a 374-amino acid protein, designated raPIT5a. raPIT5a was expressed in specific cells in the intermediate and anterior lobes of the pituitary. Recombinant raPIT5a was not secreted suggesting raPIT5a functions to inhibit intracellular proteases. Recombinant raPIT5a formed an SDS-stable complex with human granzyme B, a serine protease which induces apoptosis by activating members of the caspase enzyme family. These data suggest raPIT5a may have a role in regulating granzyme B or related enzymes and apoptosis in the pituitary gland.
我们从大鼠垂体cDNA文库中克隆了一种新型丝氨酸蛋白酶抑制剂（raPIT5a），它在结构上与丝氨酸蛋白酶抑制剂卵清蛋白亚家族的成员相关。这个新的cDNA编码一个374个氨基酸的蛋白质，命名为raPIT5a。raPIT5a在垂体中间叶和前叶的特定细胞中表达。重组raPIT5a不分泌，提示raPIT5a的功能是抑制细胞内蛋白酶。重组raPIT5a与人颗粒酶B形成了SDS稳定复合物，颗粒酶B是一种通过激活半胱天冬酶家族成员诱导细胞凋亡的丝氨酸蛋白酶。这些数据表明raPIT5a可能在调节颗粒酶B或相关酶以及垂体细胞凋亡中发挥作用。
