Cartilage Associated Protein (CRTAP)

CRTAP 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 is highly expressed in mouse growth plate proliferating chondrocytes and in cells at the chondroosseous junction. At embryonic day 15.5, it is expressed strongly in the presumptive bone collar of the diaphyses, where vascular and osteoblast invasion is initiated. Its expression is low in hypertrophic chondrocytes, and RT-PCR analysis confirmed expression in both osteoclasts and osteoblasts. Most of the Crtap protein is located within cells, although some signal was detected in the extracellular matrix.