Adenylate kinase 4, mitochondrial (AK4)

Adenylate kinase 4, mitochondrial (AK4), is a member of the adenylate kinase enzyme family localized to the mitochondrial matrix, involved in cellular energy homeostasis by regulating the balance of adenine and guanine nucleotides via phosphoryl transfer reactions[2][3]. Unlike other adenylate kinases, AK4 is reported to be catalytically inactive in vitro but retains the ability to bind nucleotides and is suggested to function primarily through protein–protein interactions—especially with the mitochondrial ADP/ATP translocase (ANT)—rather than catalysis[1]. AK4 expression is stress-responsive and is elevated in various cancers, where it is linked to cell survival, proliferation, chemoresistance, and metastasis, marking it as a potential prognostic biomarker and a candidate therapeutic target in oncology[1][2].

Other names

Adenylate kinase 4AK4AK3L1Adenylate kinase 3-like 1GTP:AMP phosphotransferase AK4ATP-AMP transphosphorylaseMitochondrial adenylate kinase-3Adenylate kinase isoenzyme 4, mitochondrialNucleoside-triphosphate-adenylate kinase

AK4 modulates mitochondrial nucleotide balance, regulates mitochondrial membrane permeability (via interaction with ANT), influences transcription factors affecting tumor progression (e.g., ATF3), and is involved in chemoresistance mechanisms (e.g., via miR‑199a‑3p and NF-κB pathway)[2].