National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
R01GM085234
米国
National Institutes of Health/National Institute of Neurological Disorders and Stroke (NIH/NINDS)
RO1NS053494
米国
National Basic Research Program of China (973 Program)
2014CB910301
中国
National Natural Science Foundation of China (NSFC)
31370821
中国
Top Talents Program of Yunnan Province
2011HA012
中国
High-level Overseas Talents of Yunnan Province
中国
China Youth 1000-Talent Program of the State Council of China
中国
Beijing Advanced Innovation Center for Structural Biology
中国
引用
ジャーナル: Nat Struct Mol Biol / 年: 2017 タイトル: Structural basis of dual Ca/pH regulation of the endolysosomal TRPML1 channel. 著者: Minghui Li / Wei K Zhang / Nicole M Benvin / Xiaoyuan Zhou / Deyuan Su / Huan Li / Shu Wang / Ioannis E Michailidis / Liang Tong / Xueming Li / Jian Yang / 要旨: The activities of organellar ion channels are often regulated by Ca and H, which are present in high concentrations in many organelles. Here we report a structural element critical for dual Ca/pH ...The activities of organellar ion channels are often regulated by Ca and H, which are present in high concentrations in many organelles. Here we report a structural element critical for dual Ca/pH regulation of TRPML1, a Ca-release channel crucial for endolysosomal function. TRPML1 mutations cause mucolipidosis type IV (MLIV), a severe lysosomal storage disorder characterized by neurodegeneration, mental retardation and blindness. We obtained crystal structures of the 213-residue luminal domain of human TRPML1 containing three missense MLIV-causing mutations. This domain forms a tetramer with a highly electronegative central pore formed by a novel luminal pore loop. Cysteine cross-linking and cryo-EM analyses confirmed that this architecture occurs in the full-length channel. Structure-function studies demonstrated that Ca and H interact with the luminal pore and exert physiologically important regulation. The MLIV-causing mutations disrupt the luminal-domain structure and cause TRPML1 mislocalization. Our study reveals the structural underpinnings of TRPML1's regulation, assembly and pathogenesis.