Biglycan, or proteoglycan-I (PG-I), and decorin, or proteoglycan-II are related but distinct small
proteoglycans found in many connective tissues. The sequence of the cDNAs encoding the core proteins indicate that the
2 proteins are composed predominantly of a series of 12 tandem repeats of a nominal 24-residue consensus leucine-rich repeat sequence
(Fisher et al., 1989) . Biglycan is a single-copy gene about 6 kb in length. In vitro studies indicate that biglycan may function in connective tissue metabolism by binding to collagen fibrils and
TGF-beta.
NCBI Summary:
The protein encoded by this gene is a small cellular or pericellular matrix proteoglycan that is closely related in structure to two other small proteoglycans, decorin and fibromodulin. The encoded protein and decorin are thought to be the result of a gene duplication. Decorin contains one attached glycosaminoglycan chain, while this protein probably contains two chains. For this reason, this protein is called biglycan. This protein is thought to function in connective tissue metabolism by binding to collagen fibrils and transfering growth factor-beta. It may promote neuronal survival. This gene is a candidate gene for the Happle syndrome.
General function
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Cellular localization
Extracellular Matrix, Secreted
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Ovarian function
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The mRNA levels for several extracellular matric components were determined in the mouse ovary at six distinct stages of the 4-day oestrous cycle ((Oksjoki et al., 1999 ). Northern analysis revealed statistically significant cyclic expression patterns for the mRNAs coding for type III, IV and VI collagens as well as for the small proteoglycan, biglycan, and for syndecan-1 and osteonectin, suggesting that cyclic changes in the production and degradation of ECM are part of normal ovarian function connected with follicular maturation, rupture and corpus luteum formation ((Oksjoki et al., 1999 ).
Expression regulated by
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Ovarian localization
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This gene was found in a rat ovarian cDNA library (Unigene)
Follicle stages
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Phenotypes
Mutations
1 mutations
Species: mouse
Mutation name: None
type: null mutation fertility: None Comment:Xu et al. (1998)
generated Bgn-deficient mice. Although apparently normal at birth, these mice displayed a phenotype characterized by
reduced growth rate and decreased bone mass. This may be the first report in which deficiency of a noncollagenous
extracellular matrix (ECM) protein leads to a skeletal phenotype that is marked by low bone mass that becomes more
obvious with age.