Carboxy-Terminal Proteolytic Processing at a Consensus Furin Cleavage Site Is a Prerequisite Event for Quail ZPC Secretion1
Carboxy-Terminal Proteolytic Processing at a Consensus Furin Cleavage Site Is a Prerequisite Event for Quail ZPC Secretion1
复制标题
共有弗林蛋白酶切割位点的羧基末端蛋白水解加工是鹌鹑 ZPC 分泌的先决条件1
作者：
T. Sasanami;M. Toriyama;M. Mori
摘要在鸟类中，一种与哺乳动物ZPC同源的糖蛋白是在发育中的卵泡的颗粒细胞中合成的。我们之前已经报道过，颗粒细胞中新合成的ZPC(ProZPC)在一个共识的Furin裂解位点被切割，在分泌之前产生成熟的ZPC。在本研究中，我们通过使用一种特定的Furin内切酶抑制剂和Furin裂解位点的定点突变来检测proZPC的蛋白水解性切割对ZPC分泌的影响。Western印迹分析表明，Furin抑制剂有效地阻断了proZPC的蛋白水解性切割和随后的ZPC分泌。一个具有切割呋喃酶突变序列的定点突变体没有从细胞中分泌出来。免疫细胞化学观察表明，在Furin抑制剂存在下产生的proZPC或由Furin裂解位点定点突变体产生的proZPC已积累在内质网中。这些结果表明，proZPC在共有的Furin裂解位点被Furin样蛋白酶切割，这种切割的失败导致它在内质网中积聚。因此，在共同的Furin裂解位点上，proZPC的C-末端的蛋白降解过程是鹌鹑ZPC分泌的先决条件。
Abstract In avian species, a glycoprotein homologous to mammalian ZPC is synthesized in the granulosa cells of developing follicles. We have previously reported that the newly synthesized ZPC (proZPC) in granulosa cells is cleaved at a consensus furin cleavage site to generate mature ZPC prior to secretion. In the present study, we examined the effect of the proteolytic cleavage of proZPC on ZPC secretion by using a specific inhibitor of furin endoprotease and site-directed mutagenesis of the furin cleavage site. Western blot analysis demonstrated that the furin inhibitor efficiently blocked both the proteolytic cleavage of proZPC and the subsequent ZPC secretion. A site-directed mutant that possessed a mutated sequence for furin cleavage was not secreted from the cells. The immunocytochemical observations indicated that proZPC produced in the presence of a furin inhibitor or those produced by the site-directed mutant of the furin cleavage site had accumulated in the endoplasmic reticulum. These results indicate that proZPC is proteolytically cleaved at the consensus furin cleavage site with furin-like protease, and the failure of this cleavage results in its accumulation in the endoplasmic reticulum. Therefore, the C-terminal proteolytic processing of proZPC at the consensus furin cleavage site is a prerequisite event for quail ZPC secretion.
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DOI：
10.1042/bj2990001
发表时间：
1994-04
期刊：
The Biochemical journal
影响因子：
--
作者：
P. Halban;J. Irminger
通讯作者：
P. Halban;J. Irminger
DOI：
10.1016/s0021-9258(18)61070-1
发表时间：
1987-07
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
P. Matsudaira
通讯作者：
P. Matsudaira
影响因子：
3.3
作者：
H. Qi;Zev Williams;P. M. Wassarman
通讯作者：
H. Qi;Zev Williams;P. M. Wassarman
影响因子：
11.4
作者：
MOLLOY, SS;THOMAS, L;THOMAS, G
通讯作者：
THOMAS, G
DOI：
10.1016/s0021-9258(19)74221-5
发表时间：
1993-12
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
M. Breslin;I. Lindberg;S. Benjannet;J P Mathis;C. Lazure;N. G. Seidah
通讯作者：
M. Breslin;I. Lindberg;S. Benjannet;J P Mathis;C. Lazure;N. G. Seidah