Angiogenin 4 (ANG4)

Angiogenin-4 is one of several murine proteins related to angiogenin. Angiogenin-4 is produced by mouse Paneth cells. It is secreted into the gut lumen and has bactericidal activity against intestinal microbes. Its expression is induced by Bacteroides thetaiotaomicron, a predominant member of the gut microflora, which thus influences gut microbial ecology and innate immunity. Angiogenin-4 protein levels are decreased significantly in vitamin D-deficient mice even in the absence of colitis. Angiogenin-4 is an angiogenic factor, using a thoracic aorta assay. Angiogenin-4 stimulates the proliferation of human IGR1 melanoma cells but does not stimulate the proliferation or migration of bovine corneal endothelial cells or primary mouse embryonic fibroblasts. Mutational analysis shows that ribonucleolytic activity is essential to angiogenesis.