Differential mechanisms of action of the mucolipin synthetic agonist, ML-SA1, on insect TRPML and mammalian TRPML1.
Differential mechanisms of action of the mucolipin synthetic agonist, ML-SA1, on insect TRPML and mammalian TRPML1.
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粘脂蛋白合成激动剂 ML-SA1 对昆虫 TRPML 和哺乳动物 TRPML1 的不同作用机制。
DOI：
10.1016/j.ceca.2014.09.004
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发表时间：
2014-12
期刊：
影响因子：
4
通讯作者：
Zhu MX
中科院分区：
文献类型：
--
作者：
Feng X;Xiong J;Lu Y;Xia X;Zhu MX
粘脂素合成激动剂1 （ML-SA1）最近被发现可以激活哺乳动物TRPML通道，并显示可以减轻溶酶体储存病、IV型粘脂质沉积症（MLIV）和C型尼曼-皮克病（NPC）细胞模型溶酶体中的脂质积累。由于ML-SA1在果蝇遗传研究中阐明TRPML通道的细胞和生理功能方面具有潜在的补充作用，我们使用全细胞、内向外和全溶酶体电生理记录检测了ML-SA1对果蝇HEK293细胞中TRPML表达的影响。我们之前的研究表明，当TRPML在HEK293细胞中表达时，果蝇TRPML在质膜和内溶酶体上都有定位和功能。我们在这里表明，在质膜上切除的内外斑块和扩大的内溶酶体液泡的全溶酶体记录中，ML-SA1未能激活TRPML，除非使用外源性磷脂酰肌醇3,5-二磷酸[PI(3,5)P2]。在1 μM ML-SA1下，TRPML对PI(3,5)P2的敏感性增加了约10倍；在10 μM ML-SA1下，PI(3,5)P2诱发的TRPML电流失活明显减缓。另一方面，通过模拟小鼠TRPML3变异-waddler （Va）突变的TRPML的组成性激活，使昆虫通道对ML-SA1单独激活敏感。此外，与昆虫的TRPML不同，小鼠的TRPML1很容易被ML-SA1激活，而不依赖于PI(3,5)P2。因此，我们的数据显示，ML-SA1作为小鼠TRPML1的真正激动剂，它作为果蝇TRPML的变构激活剂，表现出对昆虫通道开放构象的依赖性和稳定能力。
Mucolipin synthetic agonist 1 (ML-SA1) was recently identified to activate mammalian TRPML channels and shown to alleviate lipid accumulation in lysosomes of cellular models of lysosome storage diseases, mucolipidosis type IV (MLIV) and Niemann-Pick’s disease type C (NPC). Owning to its potential use in complimenting genetic studies in Drosophila melanogaster to elucidate the cellular and physiological functions of TRPML channels, we examined the effect of ML-SA1 on Drosophila TRPML expressed in HEK293 cells using whole-cell, inside-out, and whole-lysosome electrophysiological recordings. We previously showed that when expressed in HEK293 cells, Drosophila TRPML was localized and functional on both plasma membrane and endolysosome. We show here that in both inside-out patches excised from the plasma membrane and whole-lysosome recordings from enlarged endolysosome vacuoles, ML-SA1 failed to activate TRPML unless exogenous phosphatidylinositol 3,5-bisphosphate [PI(3,5)P2] was applied. At 1 μM ML-SA1, the sensitivity of TRPML to PI(3,5)P2 increased approximately by 10-fold and at 10 μM ML-SA1, the deactivation of PI(3,5)P2-evoked TRPML currents was markedly slowed. On the other hand, constitutive activation of TRPML by a mutation that mimics the varitint-waddler (Va) mutation of mouse TRPML3 rendered the insect channel sensitive to activation by ML-SA1 alone. Moreover, different from the insect TRPML, mouse TRPML1 was readily activated by ML-SA1 independent of PI(3,5)P2. Thus, our data reveal that while ML-SA1 acts as a true agonist at mouse TRPML1, it behaves as an allosteric activator of the Drosophila TRPML, showing dependence on and the ability to stabilize open conformation of the insect channels.
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影响因子：
16.6
作者：
Dong, Xian-ping;Shen, Dongbiao;Wang, Xiang;Dawson, Taylor;Li, Xinran;Zhang, Qi;Cheng, Xiping;Zhang, Yanling;Weisman, Lois S.;Delling, Markus;Xu, Haoxing
通讯作者：
Xu, Haoxing
影响因子：
11.4
作者：
Zhang, Yanling;McCartney, Amber J.;Zolov, Sergey N.;Ferguson, Cole J.;Meisler, Miriam H.;Sutton, Michael A.;Weisman, Lois S.
通讯作者：
Weisman, Lois S.
影响因子：
4.1
作者：
Whiteford, CC;Brearley, CA;Ulug, ET
通讯作者：
Ulug, ET
影响因子：
4
作者：
Rutherford AC;Traer C;Wassmer T;Pattni K;Bujny MV;Carlton JG;Stenmark H;Cullen PJ
通讯作者：
Cullen PJ
影响因子：
3.5
作者：
Sun, M;Goldin, E;Slaugenhaupt, SA
通讯作者：
Slaugenhaupt, SA