The mitochondrial calcium uniporter (MCU) is a transmembrane protein that allows the passage of calcium ions from a cell's cytosol into mitochondria. Its activity is regulated by MICU1 and MICU2, which together with the MCU make up the mitochondrial calcium uniporter complex. The MCU is one of the primary sources of mitochondria uptake of calcium, and flow is dependent on membrane potential of the inner mitochondrial membrane and the concentration of calcium in the cytosol relative to the concentration in the mitochondria. Balancing calcium concentration is necessary to increase the cell's energy supply and regulate cell death. Calcium is balanced through the MCU in conjunction with the sodium-calcium exchanger. The MCU has a very low affinity for calcium, so the cytosolic calcium concentration needs to be approximately 5-10 uM for significant transport of calcium into the mitochondria. Mitochondria are closely associated with the endoplasmic reticulum (ER), at contact sites, which contains stores of cellular calcium ions for calcium signaling. The presence of 1,4,5-triphosphate (IP3) triggers the release of calcium from these intracellular stores, which creates microdomains of high calcium concentration between the ER and the mitochondria, creating the conditions for the MCU to take up calcium.
Background References
1. Wang P et al. Elevated MCU Expression by CaMKIIdeltaB Limits Pathological Cardiac Remodeling. Circulation. 2022 Apr
2. Li C et al. Implications of MCU complex in metabolic diseases. FASEB J. 2023 Aug
Coiled-coil domain-containing protein 109A antibody
HsMCU antibody
Mitochondrial Calcium Uniporter antibody
Images
Western blot analysis of MCU on different lysates with Rabbit anti-MCU antibody (HA723563) at 1/5,000 dilution.
Lane 1: HCT 116 cell lysate (20 µg/Lane) Lane 2: PANC-1 cell lysate (20 µg/Lane) Lane 3: A549 cell lysate (20 µg/Lane) Lane 4: HeLa cell lysate (20 µg/Lane) Lane 5: COS-1 cell lysate (20 µg/Lane) Lane 6: NIH/3T3 cell lysate (20 µg/Lane) Lane 7: C2C12 cell lysate (20 µg/Lane) Lane 8: C6 cell lysate (20 µg/Lane) Lane 9: PC-12 cell lysate (20 µg/Lane) Lane 10: Mouse colon tissue lysate (20 µg/Lane) Lane 11: Mouse heart tissue lysate (20 µg/Lane) Lane 12: Mouse testis tissue lysate (20 µg/Lane) Lane 13: Rat colon tissue lysate (20 µg/Lane) Lane 14: Rat heart tissue lysate (20 µg/Lane)
Predicted band size: 40 kDa Observed band size: 33 kDa
Exposure time: 25 seconds; ECL: K1801;
4-20% SDS-PAGE gel.
Proteins were transferred to a PVDF membrane and blocked with 5% NFDM/TBST for 1 hour at room temperature. The primary antibody (HA723563) at 1/5,000 dilution was used in primary antibody dilution (K1803) at 4℃ overnight. Goat Anti-Rabbit IgG - HRP Secondary Antibody (HA1001) at 1/50,000 dilution was used for 1 hour at room temperature.
Application: IHC-Fr
Species: Mouse
Site: eye
Sample: Frozen section
Antibody concentration: 1/500
Antigen retrieval: Not required
Immunohistochemical analysis of paraffin-embedded human colon tissue with Rabbit anti-MCU antibody (HA723563) at 1/50 dilution.
The section was pre-treated using heat mediated antigen retrieval with Tris-EDTA buffer (pH 9.0) for 20 minutes. The tissues were blocked in 1% BSA for 20 minutes at room temperature, washed with ddH2O and PBS, and then probed with the primary antibody (HA723563) at 1/50 dilution for 1 hour at room temperature. The detection was performed using an HRP conjugated compact polymer system. DAB was used as the chromogen. Tissues were counterstained with hematoxylin and mounted with DPX.
Immunohistochemical analysis of paraffin-embedded human colon cancer tissue with Rabbit anti-MCU antibody (HA723563) at 1/200 dilution.
The section was pre-treated using heat mediated antigen retrieval with Tris-EDTA buffer (pH 9.0) for 20 minutes. The tissues were blocked in 1% BSA for 20 minutes at room temperature, washed with ddH2O and PBS, and then probed with the primary antibody (HA723563) at 1/200 dilution for 1 hour at room temperature. The detection was performed using an HRP conjugated compact polymer system. DAB was used as the chromogen. Tissues were counterstained with hematoxylin and mounted with DPX.
Immunocytochemistry analysis of HCT 116 cells labeling MCU with Rabbit anti-MCU antibody (HA723563) at 1/100 dilution.
Cells were fixed in 4% paraformaldehyde for 15 minutes at room temperature, permeabilized with 0.1% Triton X-100 in PBS for 15 minutes at room temperature, then blocked with 1% BSA in 10% negative goat serum for 1 hour at room temperature. Cells were then incubated with Rabbit anti-MCU antibody (HA723563) at 1/100 dilution in 1% BSA in PBST overnight at 4 ℃. Goat Anti-Rabbit IgG H&L (iFluor™ 488, HA1121) was used as the secondary antibody at 1/1,000 dilution. PBS instead of the primary antibody was used as the secondary antibody only control. Counterstained with Mitotracker. Nuclear DNA was labelled in blue with DAPI.
Immunocytochemistry analysis of NIH/3T3 cells labeling MCU with Rabbit anti-MCU antibody (HA723563) at 1/100 dilution.
Cells were fixed in 4% paraformaldehyde for 15 minutes at room temperature, permeabilized with 0.1% Triton X-100 in PBS for 15 minutes at room temperature, then blocked with 1% BSA in 10% negative goat serum for 1 hour at room temperature. Cells were then incubated with Rabbit anti-MCU antibody (HA723563) at 1/100 dilution in 1% BSA in PBST overnight at 4 ℃. Goat Anti-Rabbit IgG H&L (iFluor™ 488, HA1121) was used as the secondary antibody at 1/1,000 dilution. PBS instead of the primary antibody was used as the secondary antibody only control. Counterstained with Mitotracker. Nuclear DNA was labelled in blue with DAPI.
Immunocytochemistry analysis of C6 cells labeling MCU with Rabbit anti-MCU antibody (HA723563) at 1/100 dilution.
Cells were fixed in 4% paraformaldehyde for 15 minutes at room temperature, permeabilized with 0.1% Triton X-100 in PBS for 15 minutes at room temperature, then blocked with 1% BSA in 10% negative goat serum for 1 hour at room temperature. Cells were then incubated with Rabbit anti-MCU antibody (HA723563) at 1/100 dilution in 1% BSA in PBST overnight at 4 ℃. Goat Anti-Rabbit IgG H&L (iFluor™ 488, HA1121) was used as the secondary antibody at 1/1,000 dilution. PBS instead of the primary antibody was used as the secondary antibody only control. Counterstained with Mitotracker. Nuclear DNA was labelled in blue with DAPI.
MCU was immunoprecipitated from 0.2 mg HCT 116 cell lysate with HA723563 at 2 µg/10 µl beads. Western blot was performed from the immunoprecipitate using HA723563 at 1/5,000 dilution. HRP Conjugated Anti-Rabbit IgG for IP Nano-secondary antibody at 1/5,000 dilution was used for 1 hour at room temperature.
Lane 1: HCT 116 cell lysate (input) Lane 2: HA723563 IP in HCT 116 cell lysate Lane 3: Rabbit IgG instead of HA723563 in HCT 116 cell lysate