Adenosine monophosphate deaminase 3 (AMPD3)

Adenosine monophosphate deaminase 3 (AMPD3) is an enzyme that catalyzes the hydrolytic deamination of adenosine monophosphate (AMP) to inosine monophosphate (IMP), a key step in purine nucleotide catabolism and energy homeostasis[1][3][5]. AMPD3 is primarily expressed in erythrocytes, distinguishing it from other AMP deaminase isoforms (AMPD1 in muscle, AMPD2 in liver). It regulates cellular AMP levels, thereby modulating energy balance and erythrocyte nucleotide pools, which can affect hemoglobin oxygen affinity and tissue oxygen delivery[1]. In skeletal muscle, AMPD3 participates in metabolic adaptation, supporting endurance and influencing systemic insulin sensitivity[1][7]. Disruption of AMPD3 function (e.g., through mutation) can result in erythrocyte AMP deaminase deficiency—a benign hereditary defect[5]. Altered AMPD3 expression is also linked to disease states including certain cancers (where higher AMPD3 corresponds to less aggressive behavior and better prognosis), cardiovascular stress responses (including ischemia–reperfusion injury), and immune cell homeostasis (notably naive T cell populations)[1][5][6]. The enzyme localizes predominantly to cytosol and the endoplasmic reticulum–mitochondria interface, modulating mitochondrial function and response to energetic or oxidative stress[2]. No approved drugs directly target AMPD3 in clinical use, but the enzyme is considered a potential therapeutic target due to its central role in purine metabolism and cellular energy regulation[1][3].

Other names

AMP deaminase 3AMPD3E isoform (erythrocyte AMP deaminase)EC 3.5.4.6

Hypothetical for AMPD3-targeting molecules: modulation of purine metabolism and cellular energy status by altering AMP to IMP conversion, potentially influencing metabolic flexibility and stress responses. Related: IMP administration can attenuate tissue injury in models with altered AMPD3 activity.