Coupled Transmembrane Substrate Docking and Helical Unwinding in Intramembrane Proteolysis of Amyloid Precursor Protein.
Coupled Transmembrane Substrate Docking and Helical Unwinding in Intramembrane Proteolysis of Amyloid Precursor Protein.
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DOI：
10.1038/s41598-018-30015-6
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发表时间：
2018-08-17
影响因子：
4.6
通讯作者：
Wang C
中科院分区：
文献类型：
--
作者：
Clemente N;Abdine A;Ubarretxena-Belandia I;Wang C
膜内切割蛋白酶（I-CLiPs）在阿尔茨海默病和癌症等生理和病理过程中发挥着重要作用。然而，I-CLiPs识别底物的机制仍然知之甚少。天冬氨酸I-CLiP早老素是γ-分泌酶复合物的催化亚基，通过淀粉样蛋白前体蛋白（APPTM）跨膜结构域的膜内蛋白水解释放淀粉样蛋白-β肽（a -β s）。在此，我们利用溶液核磁共振探测了APPTM与早老素同源物（PSHs） MCMJR1和MAMRE50的底物对接，它们在核磁共振管中裂解APPTM。化学位移摄动（CSP）显示APPTM的近膜区域介导了其与MCMJR1的对接。底物与I-CLiP的结合降低了底物APPTM c端一半的酰胺质子化学位移δH的大小，表明与酶的对接削弱了螺旋氢键，并解开了底物在初始ε-裂解位点周围的跨膜螺旋。与家族性AD相关的APPTM V44M取代导致ε-裂解位点周围出现更多的CSP和螺旋解绕。与MCMJR1相比，MAMRE50裂解APPTM的速率更高，并且在APPTM中产生更多的CSP和螺旋解绕。我们的数据表明，底物跨膜螺旋的对接和螺旋解绕在膜内蛋白水解中耦合，FAD突变修饰酶/底物相互作用，为I-CLiPs和AD药物发现的机制提供了新的见解。
Intramembrane-cleaving proteases (I-CLiPs) play crucial roles in physiological and pathological processes, such as Alzheimer’s disease and cancer. However, the mechanisms of substrate recognition by I-CLiPs remain poorly understood. The aspartic I-CLiP presenilin is the catalytic subunit of the γ-secretase complex, which releases the amyloid-β peptides (Aβs) through intramembrane proteolysis of the transmembrane domain of the amyloid precursor protein (APPTM). Here we used solution NMR to probe substrate docking of APPTM to the presenilin homologs (PSHs) MCMJR1 and MAMRE50, which cleaved APPTM in the NMR tube. Chemical shift perturbation (CSP) showed juxtamembrane regions of APPTM mediate its docking to MCMJR1. Binding of the substrate to I-CLiP decreased the magnitude of amide proton chemical shifts δH at the C-terminal half of the substrate APPTM, indicating that the docking to the enzyme weakens helical hydrogen bonds and unwinds the substrate transmembrane helix around the initial ε-cleavage site. The APPTM V44M substitution linked to familial AD caused more CSP and helical unwinding around the ε-cleavage site. MAMRE50, which cleaved APPTM at a higher rate, also caused more CSP and helical unwinding in APPTM than MCMJR1. Our data suggest that docking of the substrate transmembrane helix and helical unwinding is coupled in intramembrane proteolysis and FAD mutation modifies enzyme/substrate interaction, providing novel insights into the mechanisms of I-CLiPs and AD drug discovery.
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古细菌早老素同源物 PSH 对淀粉样前体蛋白的裂解
DOI：
10.1073/pnas.1502150112
发表时间：
2015-03-17
影响因子：
11.1
作者：
Dang, Shangyu;Wu, Shenjie;Shi, Yigong
通讯作者：
Shi, Yigong
影响因子：
11.4
作者：
Arutyunova, Elena;Panwar, Pankaj;Lemieux, M. Joanne
通讯作者：
Lemieux, M. Joanne
DOI：
10.1073/pnas.0609981104
发表时间：
2007-01-16
影响因子：
11.1
作者：
Lemieux, M. Joanne;Fischer, Sarah J.;James, Michael N. G.
通讯作者：
James, Michael N. G.
影响因子：
7.7
作者：
Bai, Xiao-chen;Rajendra, Eeson;Scheres, Sjors H. W.
通讯作者：
Scheres, Sjors H. W.
影响因子：
4.8
作者：
Kienlen-Campard, Pascal;Tasiaux, Bernadette;Octave, Jean-Noel
通讯作者：
Octave, Jean-Noel