Calcium uniporter protein, mitochondrial (MCU) is a ~39 kDa protein. Channel-forming and calcium-conducting subunit of the mitochondrial inner membrane calcium uniporter complex (uniplex), which mediates calcium uptake into the mitochondrial matrix. MCU channel activity is regulated by the calcium-sensor subunits of the uniplex MICU1 and MICU2 (or MICU3). Mitochondrial calcium homeostasis plays key roles in cellular physiology and regulates ATP production, cytoplasmic calcium signals and activation of cell death pathways. Involved in buffering the amplitude of systolic calcium rises in cardiomyocytes. While dispensable for baseline homeostatic cardiac function, acts as a key regulator of short-term mitochondrial calcium loading underlying a 'fight-or-flight' response during acute stress: acts by mediating a rapid increase of mitochondrial calcium in pacemaker cells. 3. Drago, I. et al. (2012) Proceedings of the National Academy of Sciences of the United States of America 109, 12986-91. PMID: 228222135. Alam, MR. et al. (2012) The Journal of biological chemistry 287, 34445-54. PMID: 229043197. Mallilankaraman, K. et al. (2012) Nature cell biology 14, 1336-43. PMID: 231788839. Hoffman, NE. et al. (2013) Cell reports 5, 1576-1588. PMID: 2433285410. Patron, M. et al. (2014) Molecular cell 53, 726-37. PMID: 24560927 | 
