Functional and Topological Analysis of Pen-2, the Fourth Subunit of the γ-Secretase Complex (Withdrawn Publication. See vol. 299, 2023) (Retracted Article)
Functional and Topological Analysis of Pen-2, the Fourth Subunit of the γ-Secretase Complex (Withdrawn Publication. See vol. 299, 2023) (Retracted Article)
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DOI：
10.1074/jbc.m110.216978
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发表时间：
2011-04-08
影响因子：
4.8
通讯作者：
De Strooper, Bart
中科院分区：
文献类型：
--
作者：
Bammens, Leen;Chavez-Gutierrez, Lucia;De Strooper, Bart
γ -分泌酶复合体是膜内切割蛋白酶家族的一员，参与阿尔茨海默病中a β肽的产生。该复合体的四个亚基之一，早老素，包含催化位点，尽管其他三个亚基的作用还不太清楚。在这里，我们研究了最小的亚基Pen-2在体内和体外的作用。我们在Pen-2（-/-）胚胎中发现了深刻的缺口缺陷表型，证实了Pen-2在γ -分泌酶复合物中的重要作用。采用扫描半胱氨酸可及性方法研究了Pen-2（-/-）成纤维细胞的结构-功能关系。我们发现，在Pen-2疏水结构域1中的甘氨酸22和脯氨酸27对γ -分泌酶复合物的形成和稳定性至关重要。我们还证明了Pen-2的疏水结构域1和环结构域位于一个含水腔中，并且离早老素c端片段很近。我们最终证明了Pen-2对该复合物的蛋白水解活性的重要作用。我们的研究支持了这样的假设，即Pen-2不仅仅是γ -分泌酶复合物的结构成分，而且可能有助于酶的催化机制。
The gamma-secretase complex is a member of the family of intramembrane cleaving proteases, involved in the generation of the A beta peptides in Alzheimer disease. One of the four subunits of the complex, presenilin, harbors the catalytic site, although the role of the other three subunits is less well understood. Here, we studied the role of the smallest subunit, Pen-2, in vivo and in vitro. We found a profound Notch-deficiency phenotype in Pen-2(-/-) embryos confirming the essential role of Pen-2 in the gamma-secretase complex. We used Pen-2(-/-) fibroblasts to investigate the structure-function relation of Pen-2 by the scanning cysteine accessibility method. We showed that glycine 22 and proline 27 in hydrophobic domain 1 of Pen-2 are essential for complex formation and stability of gamma-secretase. We also demonstrated that hydrophobic domain 1 and the loop domain of Pen-2 are located in a water-containing cavity and are in short proximity to the presenilin C-terminal fragment. We finally demonstrated the essential role of Pen-2 for the proteolytic activity of the complex. Our study supports the hypothesis that Pen-2 is more than a structural component of the gamma-secretase complex and may contribute to the catalytic mechanism of the enzyme.