Table 1.
Summary subunits that associate with the mitochondrial Ca2+ uniporter to form a complex
| Subunit Name | No. of TMDs | Location | Direct Binding to MCU? | Subunit Category |
|---|---|---|---|---|
| MCU | 2 (3, 24, 64) | IMM (3, 13, 24, 76) | Yes (3, 24, 94) | Pore (3, 13, 24) |
| MCUb | 2 (94) | IMM (94, 102) | Yes (94, 102) | Pore (94) |
| EMRE | 1 (102, 109) | IMM (102, 109) | Yes (102, 109) | Class 1 (102, 109) |
| MICU1 | 0 (86, 102, 109) | IMS (13, 16, 62, 86, 90, 102, 109) or Matrix (46, 71) | Yes (46, 86) or No (102, 109) | Class 2 (13, 16, 62, 86, 90, 102, 109) or 3 (46, 71) |
| MICU2 | 0 (86, 102, 109) | IMS (86, 102, 109) or Matrix? | Yes (86) or No (102) | Class 2 (86, 102, 109) or 3? |
| MICU3 | 0 (91) | IMS? or Matrix? | ? | Class 2? or 3? |
| MCUR1 | 2 (70) | IMM (70, 87) | Yes (70) or No (87) | Class 1 (70, 110) or not a subunit (87) |
| SLC25A23 | 6 (47) | IMS (47) | Yes (47) | Class 1 (47) |
For subunit classifications, see also Fig. 1.
TMD, transmembrane domain; IMM, inner mitochondrial membrane; IMS, intermembrane space. Numbers in parentheses are reference numbers.