Inhibition of sonic hedgehog autoprocessing in cultured mammalian cells by sterol deprivation
Inhibition of sonic hedgehog autoprocessing in cultured mammalian cells by sterol deprivation
复制标题
DOI：
10.1073/pnas.97.13.7307
复制
发表时间：
2000-06-20
影响因子：
11.1
通讯作者：
Guy, RK
中科院分区：
文献类型：
--
作者：
Guy, RK
Sonic hedgehog(Shh)是一种信号分子，对于定义脊椎动物发育中的中枢神经系统的模式非常重要。翻译后，Shh自身蛋白降解，并将胆固醇共价连接到新形成的羧基末端，这一修饰对正常的Shh信号至关重要。有证据表明，在培养的表达小鼠Shh(MShh)的中国仓鼠卵巢细胞中，急性严重的固醇剥夺会抑制该蛋白的自动加工。这些条件使得首次对mShh的自动加工和周转速率进行了详细的动力学分析，揭示了细胞迅速降解前体和成熟的mShh，而无论甾醇含量如何，并且剥夺类固醇会增加前体降解的速度。抑制mShh自身处理也可以确定mShh前体的亚细胞定位，它聚集在高尔基体前内侧细胞内。最后，由于自身加工抑制而产生的mShh的前体形式似乎以酰胺而不是稳定的硫酯的形式积累。
Sonic hedgehog (Shh) is a signaling molecule that is important for defining patterning in the developing vertebrate central nervous system. After translation, Shh autoproteolyzes and covalently attaches cholesterol to the newly formed carboxyl terminus, a modification crucial for normal Shh signaling. Presented here is evidence that acute severe sterol deprivation in cultured Chinese hamster ovary cells expressing mouse Shh (mShh) inhibits autoprocessing of the protein. These conditions allowed the first detailed kinetic analysis of mShh autoprocessing and turnover rates revealing that cells rapidly degrade both precursor and mature mShh regardless of sterol content and sterol deprivation increases the rate of precursor degradation. Inhibition of mShh autoprocessing also allowed the determination of the subcellular localization of mShh precursor which accumulates in a pre-medial Golgi intracellular compartment. Finally, the precursor form of mShh that results from autoprocessing inhibition appears to accumulate as an amide rather than a stable thioester.