Adenylate kinase 2, mitochondrial (AK2)

Adenylate kinase 2, mitochondrial (AK2), is an enzyme located in the intermembrane space of mitochondria. It catalyzes the reversible phosphorylation of AMP and ATP to form two ADP molecules, playing a central role in cellular energy homeostasis and adenine nucleotide metabolism. AK2 is uniquely expressed in hematopoietic progenitor cells and the inner ear. In humans, AK2 deficiency causes reticular dysgenesis, a rare and severe form of combined immunodeficiency characterized by early differentiation arrest in the myeloid lineage, impaired lymphoid development, fatal infections, and sensorineural deafness. No direct pharmacological modulators of AK2 are currently approved; the main intervention for AK2 deficiency is allogeneic hematopoietic stem cell transplantation. AK2 is classified as an enzyme, specifically a nucleoside monophosphate kinase, with essential roles in nucleotide homeostasis, mitochondrial energy transfer, regulation of apoptosis, and the differentiation of hematopoietic cells.

Other names

AK2Adenylate kinase 2Mitochondrial adenylate kinase 2Adenylate kinase isoenzyme 2Adenylate monophosphate kinaseATP-AMP transphosphorylase 2ATP:AMP phosphotransferaseTestis secretory sperm-binding protein Li 220n

No validated therapeutic drugs with a defined mechanism directly target AK2; gene therapy or hematopoietic stem cell transplantation are treatment approaches for related deficiency, not small-molecule inhibition or activation.