Medical Anatomy Commons^™

Micu1 Controls Both The Threshold And Cooperative Activation Of The Mitochondrial Ca(2+) Uniporter., György Csordás, Tünde Golenár, Erin L Seifert, Kimberli J Kamer, Yasemin Sancak, Fabiana Perocchi, Cynthia Moffat, David Weaver, Sergio De La Fuente Perez, Roman Bogorad, Victor Koteliansky, Jeffrey Adijanto, Vamsi K Mootha, György Hajnóczky

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Mitochondrial Ca(2+) uptake via the uniporter is central to cell metabolism, signaling, and survival. Recent studies identified MCU as the uniporter's likely pore and MICU1, an EF-hand protein, as its critical regulator. How this complex decodes dynamic cytoplasmic [Ca(2+)] ([Ca(2+)]c) signals, to tune out small [Ca(2+)]c increases yet permit pulse transmission, remains unknown. We report that loss of MICU1 in mouse liver and cultured cells causes mitochondrial Ca(2+) accumulation during small [Ca(2+)]c elevations but an attenuated response to agonist-induced [Ca(2+)]c pulses. The latter reflects loss of positive cooperativity, likely via the EF-hands. MICU1 faces the intermembrane space and responds to …