Structural insights into the Ca2+-dependent gating of the human mitochondrial calcium uniporter

Autor: Yan Wang, Yan Han, Ji She, Nam X Nguyen, Vamsi K Mootha, Xiao-chen Bai, Youxing Jiang
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: eLife, Vol 9 (2020)
Druh dokumentu: article
ISSN: 2050-084X
DOI: 10.7554/eLife.60513
Popis: Mitochondrial Ca2+ uptake is mediated by an inner mitochondrial membrane protein called the mitochondrial calcium uniporter. In humans, the uniporter functions as a holocomplex consisting of MCU, EMRE, MICU1 and MICU2, among which MCU and EMRE form a subcomplex and function as the conductive channel while MICU1 and MICU2 are EF-hand proteins that regulate the channel activity in a Ca2+-dependent manner. Here, we present the EM structures of the human mitochondrial calcium uniporter holocomplex (uniplex) in the presence and absence of Ca2+, revealing distinct Ca2+ dependent assembly of the uniplex. Our structural observations suggest that Ca2+ changes the dimerization interaction between MICU1 and MICU2, which in turn determines how the MICU1-MICU2 subcomplex interacts with the MCU-EMRE channel and, consequently, changes the distribution of the uniplex assemblies between the blocked and unblocked states.
Databáze: Directory of Open Access Journals
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