Grimm Christian, Jörs Simone, Saldanha S Adrian, Obukhov Alexander G, Pan Bifeng, Oshima Kazuo, Cuajungco Math P, Chase Peter, Hodder Peter, Heller Stefan
Departments of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA.
Chem Biol. 2010 Feb 26;17(2):135-48. doi: 10.1016/j.chembiol.2009.12.016.
We conducted a high-throughput screen for small molecule activators of the TRPML3 ion channel, which, when mutated, causes deafness and pigmentation defects. Cheminformatics analyses of the 53 identified and confirmed compounds revealed nine different chemical scaffolds and 20 singletons. We found that agonists strongly potentiated TRPML3 activation with low extracytosolic [Na(+)]. This synergism revealed the existence of distinct and cooperative activation mechanisms and a wide dynamic range of TRPML3 activity. Testing compounds on TRPML3-expressing sensory hair cells revealed the absence of activator-responsive channels. Epidermal melanocytes showed only weak or no responses to the compounds. These results suggest that TRPML3 in native cells might be absent from the plasma membrane or that the protein is a subunit of heteromeric channels that are nonresponsive to the activators identified in this screen.
我们对瞬时受体电位通道M型3（TRPML3）离子通道的小分子激活剂进行了高通量筛选，该离子通道发生突变时会导致耳聋和色素沉着缺陷。对53种已鉴定和确认的化合物进行的化学信息学分析揭示了9种不同的化学支架和20种单一化合物。我们发现，激动剂在低胞外[Na⁺]浓度下能强烈增强TRPML3的激活。这种协同作用揭示了不同且协同的激活机制以及TRPML3活性的广泛动态范围。在表达TRPML3的感觉毛细胞上测试化合物，结果显示不存在激活剂响应通道。表皮黑素细胞对这些化合物仅表现出微弱反应或无反应。这些结果表明，天然细胞中的TRPML3可能不存在于质膜上，或者该蛋白是对本筛选中鉴定出的激活剂无反应的异源通道的一个亚基。
