UNIPROT #

O00300

PROTEIN NAME

Osteoprotegerin

SYNONYMS

MGC29565 antibody; OCIF antibody; OPG antibody; Osteoclastogenesis inhibitory factor antibody; Osteoprotegerin antibody; PDB5 antibody; TNF receptor superfamily member 11b antibody; TNFRSF 11B antibody; TNFRSF11B antibody; TR 1 antibody; TR1 antibody; TR11B_HUMAN antibody; Tumor necrosis factor receptor superfamily member 11B antibody

TISSUE SPECIFICITY

Highly expressed in adult lung, heart, kidney, liver, spleen, thymus, prostate, ovary, small intestine, thyroid, lymph node, trachea, adrenal gland, testis, and bone marrow. Detected at very low levels in brain, placenta and skeletal muscle. Highly expressed in fetal kidney, liver and lung.

POST-TRANSLATIONAL MODIFICATION

N-glycosylated. Contains sialic acid residues.; The N-terminus is blocked.

SUBCELLULAR LOCATION

Secreted.

FUNCTION

Bone morphogenesis and remodeling involve the formation of bone from osteoblasts and the resorption of bone by osteoclasts. The cytokine osteoprotegerin (OPG), also designated osteoclastogenesis inhibitory factor (OCIF), is known to inhibit osteoclast formation. A secreted glycoprotein, OPG is a member of the TNF receptor family that increases bone density and volume. OPG is thought to inhibit osteoclastogenesis by disrupting the cell-to-cell signaling between osteoblastic stromal cells and osteoclast progenitors. OPG is known to bind to TRAIL, a death domain-containing protein, and to inhibit TRAIL apoptosis in Jurkat cells. OPG also binds to osteoclast differentiation factor (ODF), also known as TRANCE/RANKL, a membrane-bound protein belonging to the TNF ligand family. Both TNFα and TNFβ upregulate OPG expression, while the bone resorbing agent prostaglandin E2 downregulates OPG.