SLC25A5

Solute carrier family 25 (mitochondrial carrier; adenine nucleotide translocator), member 5 is a is_associated_with::protein that in humans is encoded by the SLC25A5 is_associated_with::gene. This protein functions as an antiporter for ADP/ATP exchange between the mitochondrial matrix and cytoplasm. As a result, it plays a key role in maintaining mitochondrial membrane potential and inhibiting apoptosis and has been targeted for treating cancer.

Structure
The SLC25A5 gene consists of 4 exons, while its encoded protein forms a homodimer embedded in the inner mitochondrial membrane. The entire protein is composed of 300-320 amino acid residues folded into six transmembrane helices. The human genome contains several non-transcribed pseudogenes of this gene.

Function
This gene is a member of the mitochondrial carrier subfamily of solute carrier protein genes. The product of this gene, adenine nucleotide translocator 2 (ANT2), functions as a gated pore that translocates ADP from the mitochondrial matrix into the cytoplasm. As a result of its antiporter function, ANT2 maintains mitochondrial membrane potential by regulating ADP/ATP ratios in oxidative phosphorylation. ANT2 facilitates uncoupling of the mitochondrial membrane when acylated by SIRT4. In addition, ANT2 plays a role in inhibiting apoptosis, and suppressing the expression of this gene has been shown to induce apoptosis and inhibit tumor growth. Though ANT2 is highly conserved and ubiquitously expressed, its expression levels and, accordingly, biological function, may vary depending on tissue type. It is specifically expressed in undifferentiated cells and renewable tissues while maintaining low expression levels in differentiated cells. Due to its expression profile, it has been used as a growth marker and targeted for studies in tumor cell growth.

Clinical Significance
Overexpression of ANT2 has been linked to tumor cell growth and attributed to its anti-apoptotic function. Nonetheless, specific silencing of the ANT2 gene failed to induce apoptosis to tumor cells without a combining treatment with lonidamine, an anti-tumor drug, thus indicating that additional factors may be involved to mediate membrane permeability and programmed cell death.

In the brain, ANT2 participates as part of the post-synaptic density (PSD) and, thus, has been associated with is_associated_with::X-linked intellectual disability (XLID).

Interactions
SLC25A5 has been shown to interact with:
 * is_associated_with::SIRT4