OTOR, also called Otoraplin and MIAL, is a secreted cytokine and a member of the melanoma-inhibiting activity gene family. Members of this family which also includes MIA, MIA2, and TANGO share a SRC homology-3 (SH3)-like domain. OTOR appears to be involved in early chondrogenesis of the otic capsule, which is required for normal inner ear development and auditory function. OTOR is highly homologous to MIA/cartilage-derived retinoic acid-sensitive protein (CD-RAP), which is a cartilage-specific protein that is also expressed in malignant melanoma cells. The 111 amino acid mature human otoraplin contains 1 SH3 domain (46-107 amino acids) and a Tyr at position 50 that is reportedly sulfated. Otoraplin takes part in the initiation of periotic mesenchyme chondrogenesis. Recombinant human Otoraplin (OTOR) produced in CHO cells is a single non-glycosylated polypeptide chain containing 111 amino acids. A fully biologically active molecule, rhOTOR has a molecular mass of 14-15 kDa analyzed by reducing SDS-PAGE and is obtained by chromatographic techniques at GenScript.
