Homozygosity for a missense mutation in SERPINH1, which encodes the collagen chaperone protein HSP47, results in severe recessive osteogenesis imperfecta.
Am J Hum Genet
; 86(3): 389-98, 2010 Mar 12.
Article
em En
| MEDLINE
| ID: mdl-20188343
ABSTRACT
Osteogenesis imperfecta (OI) is characterized by bone fragility and fractures that may be accompanied by bone deformity, dentinogenesis imperfecta, short stature, and shortened life span. About 90% of individuals with OI have dominant mutations in the type I collagen genes COL1A1 and COL1A2. Recessive forms of OI resulting from mutations in collagen-modifying enzymes and chaperones CRTAP, LEPRE1, PPIB, and FKBP10 have recently been identified. We have identified an autosomal-recessive missense mutation (c.233T>C, p.Leu78Pro) in SERPINH1, which encodes the collagen chaperone-like protein HSP47, that leads to a severe OI phenotype. The mutation results in degradation of the endoplasmic reticulum resident HSP47 via the proteasome. Type I procollagen accumulates in the Golgi of fibroblasts from the affected individual and a population of the secreted type I procollagen is protease sensitive. These findings suggest that HSP47 monitors the integrity of the triple helix of type I procollagen at the ER/cis-Golgi boundary and, when absent, the rate of transit from the ER to the Golgi is increased and helical structure is compromised. The normal 3-hydroxylation of the prolyl residue at position 986 of the triple helical domain of proalpha1(I) chains places the role of HSP47 downstream from the CRTAP/P3H1/CyPB complex that is involved in prolyl 3-hydroxylation. Identification of this mutation in SERPINH1 gives further insight into critical steps of the collagen biosynthetic pathway and the molecular pathogenesis of OI.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Osteogênese Imperfeita
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Mutação de Sentido Incorreto
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Proteínas de Choque Térmico HSP47
Tipo de estudo:
Diagnostic_studies
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Prognostic_studies
Limite:
Child, preschool
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Female
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Humans
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Male
Idioma:
En
Ano de publicação:
2010
Tipo de documento:
Article