Proteoglycan-Lb, a small dermatan sulfate proteoglycan expressed in embryonic chick epiphyseal cartilage, is structurally related to osteoinductive factor.
We have isolated cDNA clones encoding the core protein of PG-Lb, proteoglycan which has been shown to be preferentially expressed in the zone of flattened chondrocytes of the developing chick limb cartilage (Shinomura, T., Kimata, K., Oike, Y., Yano, S., and Suzuki, S. (1984) Dev. Biol. 103, 211-220). The deduced amino acid sequence from the cDNA analysis indicates the presence of consensus leucine-rich repeats which are present in other small proteoglycans, decorin, biglycan, and fibromodulin. However, the homology analysis revealed that chick PG-Lb showed a higher homology (about 50% in the region containing leucine-rich repeats) to human osteoinductive factor, OIF, rather than to the other small proteoglycans. Furthermore, 6 cysteine residues are detected in both PG-Lb and OIF with invariant relative positions. Therefore, such an evolutionarily conserved structure in the PG-Lb core protein might be involved in some important biological functions of this molecule. In close relation to the structural similarity to OIF, the unique expression of PG-Lb in the ossifying area of cartilage suggested the possible participation of this proteoglycan in osteogenic processes.
Shinomura
T
T
Institute for Molecular Science of Medicine, Aichi Medical University, Japan.
Kimata
K
K
D000595:Amino Acid Sequence; D000818:Animals; D030161:Avian Proteins; D001483:Base Sequence; D015152:Blotting, Northern; D015153:Blotting, Western; D002356:Cartilage / Q000378:metabolism*; D002642:Chick Embryo; D011508:Chondroitin Sulfate Proteoglycans / Q000235:genetics*; D004247:DNA / Q000235:genetics; D003871:Dermatan Sulfate / Q000235:genetics*; D004591:Electrophoresis, Polyacrylamide Gel; D006023:Glycoproteins / Q000235:genetics*; D006132:Growth Plate / Q000378:metabolism*; D006133:Growth Substances / Q000235:genetics*; D008969:Molecular Sequence Data; D011233:Precipitin Tests; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid
D030161:Avian Proteins; D011508:Chondroitin Sulfate Proteoglycans; D006023:Glycoproteins; D006133:Growth Substances; D012333:RNA, Messenger; C032649:dermatan sulfate proteoglycan; C072190:DSPG3 protein, chicken; D003871:Dermatan Sulfate; D004247:DNA