Adenylate kinases (AKs) are nucleoside monophosphate kinases, which catalyse the phosphorylation of AMP by using ATP or GTP as phosphate donors. In humans, nine different AK isoenzymes have been identified (AK1-9). This entry includes AK1 and AK5. AK1 is the major cytosolic isoform and is present in all tissues with its highest expression levels in skeletal muscle, brain and erythrocytes []. AK5 expression is limited to brain tissue [].
