LACC1

Purine nucleoside enzyme that catalyzes the phosphorolysis of adenosine, guanosine and inosine nucleosides, yielding D-ribose 1-phosphate and the respective free bases, adenine, guanine and hypoxanthine. Also catalyzes the phosphorolysis of S-methyl-5'-thioadenosine into adenine and S-methyl-5-thio-alpha-D-ribose 1-phosphate. Also has adenosine deaminase activity. Acts as a regulator of innate immunity in macrophages by modulating the purine nucleotide metabolism, thereby regulating the metabolic function and bioenergetic state of macrophages. Enables a purine nucleotide cycle between adenosine and inosine monophosphate and adenylosuccinate that prevents cytoplasmic acidification and balances the cytoplasmic-mitochondrial redox interface. The purine nucleotide cycle consumes aspartate and releases fumarate in a manner involving fatty acid oxidation and ATP-citrate lyase activity. Participates in pattern recognition receptor (PRR)-induced cytokines in macrophages: associates with the NOD2-signaling complex and promotes optimal NOD2-induced signaling, cytokine secretion and bacterial clearance. Localizes to the endoplasmic reticulum upon PRR stimulation of macrophages and associates with endoplasmic reticulum-stress sensors, promoting the endoplasmic reticulum unfolded protein response (UPR). Component of L-arginine metabolism in activated macrophages supporting anti-inflammatory and antibacterial macrophage effector functions. Cleaves L-citrulline, a product of L-arginine metabolized via NOS2, to yield isocyanate, a reactive carbonyl species-like cytotoxin, and L-ornithine, a precursor in polyamine biosynthesis. Through L-ornithine controls cellular polyamine pools likely triggering polyamine-mediated proinflammatory cytokine suppression and autophagy stimulation. Directly interacts with components of autophagy machinery to regulate macrophage metabolism and bacterial phagocytosis. Acts downstream of the energy sensor AMP-activated protein kinase (AMPK) to promote autophagy associated to lipid droplets generation providing fatty acids for mitochondrial respiration. Does not show laccase activity..

Function from UniProtKB (Q8IV20), read 2026-09-23. CC BY 4.0.