Cartilage associated protein is a protein that in humans is encoded by the CRTAP gene.
The protein encoded by this gene is similar to the chicken and mouse CRTAP genes. The encoded protein is a scaffolding protein that may influence the activity of at least one member of the cytohesin/ARNO family in response to specific cellular stimuli.
CRTAP forms a tight protein complex with two other enzymes involved in post-translational modification: Leprecan (P3H1) and PPIB. In this complex, CRTAP acts as a collagen-binding site, capturing substrates for subsequent enzymatic processing by P3H1 and PPIB. Notably, CRTAP exhibits a folding pattern similar to the N-terminal domain of P3H1.
Mutations in the CRTAP gene are associated with osteogenesis imperfecta, types VII and IIB, a connective tissue disorder characterized by bone fragility and low bone mass.