The putative tumour suppressor EXT1 alters the expression of cell-surface heparan sulfate

• Published in: Nature genetics Vol. 19; no. 2; pp. 158 - 161
• Main Authors: Tufaro, Frank, McCormick, Craig, Leduc, Yves, Martindale, Diane, Mattison, Kirsten, Esford, Lesley, Dyer, Angela
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group 01.06.1998
• Subjects: Animals; Biological and medical sciences; Cell Line; Chromosomes, Human, Pair 11; Chromosomes, Human, Pair 8; Diseases of the osteoarticular system; Exostoses, Multiple Hereditary - genetics; Gene Expression Regulation; Genes, Tumor Suppressor; Genetic Linkage; Heparitin Sulfate - biosynthesis; Heparitin Sulfate - genetics; Humans; Malformations and congenital and or hereditary diseases involving bones. Joint deformations; Medical sciences; Mice; Molecular Weight; N-Acetylglucosaminyltransferases; Proteins - genetics; Proteins - physiology; Surface Properties; Human; Transmembrane protein; Cell function; Diseases of the osteoarticular system; Glycoproteins; Gene expression; Cell surface; Genetic disease; Cell line; Glycosaminoglycan; Genetics; Heparitin sulfate; Mutation; Localization; Osteochondrodysplasia; Multiple cartilaginous exostosis; Endoplasmic reticulum; Tumor suppressor gene
• ISSN: 1061-4036; 1546-1718
• DOI: 10.1038/514

Hereditary multiple exostoses (HME) is an autosomal dominant disorder characterized by the formation of cartilage-capped tumours (exostoses) that develop from the growth plate of endochondral bone. This condition can lead to skeletal abnormalities, short stature and malignant transformation of exostoses to chondrosarcomas or osteosarcomas. Linkage analyses have identified three different genes for HME, EXT1 on 8q24.1, EXT2 on 11p11-13 and EXT3 on 19p (refs 6-9). Most HME cases have been attributed to missense or frameshift mutations in these tumour-supressor genes, whose functions have remained obscure. Here, we show that EXT1 is an ER-resident type II transmembrane glycoprotein whose expression in cells results in the alteration of the synthesis and display of cell surface heparan sulfate glycosaminoglycans (GAGs). Two EXT1 variants containing aetiologic missense mutations failed to alter cell-surface glycosaminoglycans, despite retaining their ER-localization.