Musclin, also designated osteocrin (Ostn), shows no homology with any known genes, except that it contains two conserved sequence motifs homologous to the natriuretic peptide family. Musclin is highly expressed in cells of osteoblast lineage and in skeletal muscle tissue, where it is tightly regulated by nutritional changes. It is secreted as either a full-length precursor protein or a processed form. A novel skeletal muscle-derived secretory factor, Musclin may play a role in bone formation and be linked to glucose metabolism. Studies indicate that insulin increases Musclin expression, whereas epinephrine, isoproterenol and forskolin reduce its expression. Musclin is expressed in osteoblasts and young osteocytes. In mouse tissues, expression is bone-specific, although minimal Musclin expression is also observed in muscle, kidney, testis and heart tissues.

Predicted to enable signaling receptor binding activity. Involved in negative regulation of dendrite extension. Predicted to be active in extracellular space. [provided by Alliance of Genome Resources, Apr 2022]