Involved in skeletal muscle regeneration, specifically at the onset of cell fusion. Also involved in macrophage-derived giant cells (MGC) and osteoclast formation from mononuclear precursors.

Isoform 1 is expressed in placenta and skeletal, cardiac, and smooth muscle. Isoform 2 seems to be expressed only in placenta or in embryo and fetus. Both forms were expressed in some tumor cells lines. Not detected in brain, lung, liver, kidney or pancreas.

Contains 1 disintegrin domain.
Contains 1 EGF-like domain.
Contains 1 peptidase M12B domain.

The cysteine-rich domain supports cell adhesion through syndecans and triggers signaling events that lead to beta-1 integrin-dependent cell spreading. In carcinomas cells the binding of this domain to syndecans does not allow the integrin-mediated cell spreading.
The conserved cysteine present in the cysteine-switch motif binds the catalytic zinc ion, thus inhibiting the enzyme. The dissociation of the cysteine from the zinc ion upon the activation-peptide release activates the enzyme.

The precursor is cleaved by a furin endopeptidase.

Secreted and Cell membrane.