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. Colocalizes with aggresomes, which are aggregates of misfolded proteins, at the centrosome. Colocalizes with aggresomes, which are aggregates of misfolded proteins, at the centrosome. Predominantly expressed in resting chondrocytes. Transiently expressed in the developing mouse skeleton between day 13.5 dpc of embryonic development and 5 months of postnatal development. Absent in undifferentiated mesenchymal cells. Isoforms 1 and 3 are significantly increased with the onset of chondrogenesis, whereas Isoforms 2 and 4 are detected at a later stage. Expression inhibited by TGFB1, and weakly inhibited by BMP2. 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. Sulfated on one or two tyrosine residues within the tryptic peptide 121-135. Belongs to the UCMA family.