SLC25A25
Domain
The regulatory N-terminal domain/NTD, binds calcium in the mitochondrial intermembrane space and regulates the antiporter activity of the transmembrane domain/TMD. In absence of calcium, the apo form of the N-terminal domain is intrinsically disordered and binds to the transmembrane domain, inhibiting the transporter activity. Binding of calcium leads to a major conformational change and abolishes the interaction with the transmembrane domain and the inhibition of the transporter activity.
The C-terminal mitochondrial carrier domain/transmembrane domain/TMD bears the transmembrane transporter activity.
Linker region/H9 could directly block the transport of substrates across the transporter.
Function
Electroneutral antiporter that most probably mediates the transport of adenyl nucleotides through the inner mitochondrial membrane. Originally identified as an ATP-magnesium/inorganic phosphate antiporter, it could have a broader specificity for adenyl nucleotides. By regulating the mitochondrial matrix adenyl nucleotide pool could adapt to changing cellular energetic demands and indirectly regulate adenyl nucleotide-dependent metabolic pathways.
Sequence Similarities
Belongs to the mitochondrial carrier (TC 2.A.29) family.
Tissue Specificity
Widely expressed. Expressed in fetal and adult liver, skeletal muscle, testis, ovary, hippocampus and caudate nucleus.
Isoform 1
Expressed in all tissues tested.
Isoform 2
Expression is restricted to kidney and lung.
Cellular localization
- Mitochondrion inner membrane
- Multi-pass membrane protein
Alternative names
APC3, KIAA1896, MCSC3, SCAMC2, UNQ549/PRO1106, SLC25A25, Mitochondrial adenyl nucleotide antiporter SLC25A25, Mitochondrial ATP-Mg/Pi carrier protein 3, Mitochondrial Ca(2+)-dependent solute carrier protein 3, Short calcium-binding mitochondrial carrier protein 2, Solute carrier family 25 member 25, SCaMC-2