Involved in mediating cell attachment and inducing integrin-mediated cellular reactions, such as cell spreading and alterations in cell morphology. Homotrimer. Interacts with FBN1, fibronectin and integrins ITGA1/ITGB1 and ITGA2/ITGB1. Integrin ITGA1/ITGB1 binds to a unique site within COL16A1 located close to its C-terminal end between collagenous domains COL1-COL3 (By similarity). Expressed in most tissues examined with highest levels of expression observed in heart. Strongly expressed in cortical and medullar regions of kidney and more weakly expressed in lung. Also detected in the ciliary muscle of the eye, on the serosa layer lining the muscularis externa of intestinal tissue, and in the perimysium membrane lining both the cardiac muscle bundle and the smooth muscle tissue of the small intestine. Strongly stained in particulate or granular structures. Not detected in brain or skeletal muscle. At 8 dpc no significant expression of mRNA or protein is observed, but strong signals are observed in placental trophoblasts. By 11 dpc weak positive signals are observed in heart. During later stages of development, stronger expression is observed in a variety of tissues, particularly in the atrial and ventricular walls of the developing heart, spinal root neural fibers and skin. This sequence defines eighteen different domains, nine triple-helical domains (COL9 to COL1) and ten non-triple-helical domains (NC10 to NC1). The numerous interruptions in the triple helix may make this molecule either elastic or flexible. Prolines at the third position of the tripeptide repeating unit (G-X-Y) are hydroxylated in some or all of the chains. Glycosylated. Belongs to the fibril-associated collagens with interrupted helices (FACIT) family.