Occurrence of PG-Lb, a leucine-rich small chondroitin/dermatan sulphate proteoglycan in mammalian epiphyseal cartilage: molecular cloning and sequence analysis of the mouse cDNA.
PG-Lb is a chondroitin/dermatan sulphate proteoglycan first isolated from chick embryo limb cartilage. It had been assumed that osteoglycin represents its mammalian homologue. However, partial amino acid sequences of a novel proteoglycan from bovine epiphyseal cartilage showed high identity with those of chick PG-Lb (P. Neame, L. Rosenberg and M. Höök, personal communication). Reverse transcriptase PCR using degenerate oligonucleotide primers gave a cDNA fragment that might correspond to mouse PG-Lb. We isolated a clone from a cDNA library of newborn mouse epiphyseal cartilage using the cDNA fragment as a probe. The cloned cDNA was 1430 bp long and contained a 966 bp open reading frame which encoded the core protein consisting of 322 amino acid residues. The deduced amino acid sequence showed a high overall identity with chick PG-Lb (about 62%, reaching about 80% over the carboxyl two-thirds). In addition, the amino acid sequence contained a signal peptide, six cysteine residues at the invariant relative position to chick PG-Lb, six leucine-rich repeats at the carboxyl two-thirds, three possible glycosaminoglycan-attachment sites (two sites at the N-terminal side and one site at the C-terminus) and two possible Asn-glycosylation sites near the C-terminus. Northernblot analysis demonstrated the specific expression of a 1.5 kb message in cartilage and testis. These structural features and the characteristic expression suggest that the cloned molecule is mouse PG-Lb.
Kurita
K
K
Institute for Molecular Science of Medicine, Aichi Medical University, Japan.
Shinomura
T
T
Ujita
M
M
Zako
M
M
Kida
D
D
Iwata
H
H
Kimata
K
K
D000595:Amino Acid Sequence; D000818:Animals; D000831:Animals, Newborn; D030161:Avian Proteins; D001483:Base Sequence; D002358:Cartilage, Articular / Q000378:metabolism*; D002417:Cattle; D002642:Chick Embryo; D011508:Chondroitin Sulfate Proteoglycans / Q000235:genetics* / Q000378:metabolism*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics*; D003871:Dermatan Sulfate / Q000235:genetics* / Q000378:metabolism*; D004838:Epiphyses / Q000378:metabolism*; D015723:Gene Library; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D011509:Proteoglycans; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D000071232:Small Leucine-Rich Proteoglycans; D014018:Tissue Distribution
D030161:Avian Proteins; D011508:Chondroitin Sulfate Proteoglycans; D018076:DNA, Complementary; C504412:Epyc protein, mouse; D011509:Proteoglycans; D012333:RNA, Messenger; D000071232:Small Leucine-Rich Proteoglycans; C072190:DSPG3 protein, chicken; D003871:Dermatan Sulfate