ATPase inhibitor, mitochondrial is an enzyme that in humans is encoded by the ATPIF1 gene. This gene encodes a mitochondrial ATPase inhibitor. Alternative splicing occurs at this locus and three transcript variants encoding distinct isoforms have been identified. It prevents ATPase from switching to ATP hydrolysis during collapse of the electrochemical gradient, for example during oxygen deprivation. ATP synthase inhibitor forms a one-to-one complex with the F1 ATPase, possibly by binding at the alpha-beta interface. It is thought to inhibit ATP synthesis by preventing the release of ATP. The inhibitor has two oligomeric states, dimer (the active state) and tetramer. At low pH, the inhibitor forms a dimer via antiparallel coiled coil interactions between the C-terminal regions of two monomers. At high pH, the inhibitor forms tetramers and higher oligomers by coiled coil interactions involving the N terminus and inhibitory region, thus preventing the inhibitory activity.
Background References
1. Domínguez-Zorita S et al. The ATPase Inhibitory Factor 1 is a Tissue-Specific Physiological Regulator of the Structure and Function of Mitochondrial ATP Synthase: A Closer Look Into Neuronal Function. Front Physiol. 2022 Mar
2. Cuezva JM et al. The ATPase Inhibitory Factor 1 (IF1) Contributes to the Warburg Effect and Is Regulated by Its Phosphorylation in S39 by a Protein Kinase A-like Activity. Cancers (Basel). 2024 Feb
Western blot analysis of ATPase Inhibitory Factor 1 / IF1 on different lysates with Rabbit anti-ATPase Inhibitory Factor 1 / IF1 antibody (HA723890) at 1/5,000 dilution.
Lane 1: HeLa cell lysate Lane 2: K-562 cell lysate Lane 3: MCF7 cell lysate Lane 4: HepG2 cell lysate Lane 5: HT-29 cell lysate Lane 6: COS-1 cell lysate
Lysates/proteins at 20 µg/Lane.
Predicted band size: 12 kDa Observed band size: 12 kDa
Exposure time: 1 minute 50 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 (HA723890) 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.
Immunocytochemistry analysis of HeLa cells labeling ATPase Inhibitory Factor 1 / IF1 with Rabbit anti-ATPase Inhibitory Factor 1 / IF1 antibody (HA723890) at 1/1,000 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-ATPase Inhibitory Factor 1 / IF1 antibody (HA723890) at 1/1,000 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.
Immunohistochemical analysis of paraffin-embedded human colon carcinoma tissue with Rabbit anti-ATPase Inhibitory Factor 1 / IF1 antibody (HA723890) at 1/5,000 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 (HA723890) at 1/5,000 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 liver tissue with Rabbit anti-ATPase Inhibitory Factor 1 / IF1 antibody (HA723890) at 1/5,000 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 (HA723890) at 1/5,000 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 heart tissue with Rabbit anti-ATPase Inhibitory Factor 1 / IF1 antibody (HA723890) at 1/20,000 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 (HA723890) at 1/20,000 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.
Flow cytometric analysis of HeLa cells labeling ATPase Inhibitory Factor 1 / IF1.
Cells were fixed and permeabilized. Then stained with the primary antibody (HA723890, 1/1,000) (red) compared with Rabbit IgG Isotype Control (green). After incubation of the primary antibody at +4℃ for an hour, the cells were stained with a iFluor™ 488 conjugate-Goat anti-Rabbit IgG Secondary antibody (HA1121) at 1/1,000 dilution for 30 minutes at +4℃. Unlabelled sample was used as a control (cells without incubation with primary antibody; black).
ATPase Inhibitory Factor 1 / IF1 was immunoprecipitated from 0.2 mg K-562 cell lysate with HA723890 at 2 µg/10 µl beads. Western blot was performed from the immunoprecipitate using HA723890 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: K-562 cell lysate (input) Lane 2: HA723890 IP in K-562 cell lysate Lane 3: Rabbit IgG instead of HA723890 in K-562 cell lysate