Unique Cartilage Matrix Associated Protein (UCMA)

UCMA may be involved in the negative control of osteogenic differentiation of osteochondrogenic precursor cells in peripheral zones of fetal cartilage and at the cartilage-bone interface. Proteolytically cleaved by a furin-like convertase to generate a persistent C-terminal fragment found in almost the entire cartilage matrix, and affecting osteoblast differentiation. Predominantly expressed in resting chondrocytes.

Cartilage is composed of specialized cells called chondroblasts that produce a large amount of extracellular matrix composed of Type II collagen (except fibrocartilage which also contains type I collagen) fibers, abundant ground substance rich in proteoglycan, and elastin fibers. Chondroblasts that get caught in the matrix are called chondrocytes.