EXT2

This gene encodes one of two glycosyltransferases involved in the chain elongation step of heparan sulfate biosynthesis. Mutations in this gene cause the type II form of multiple exostoses. Alternatively spliced transcript variants encoding different isoforms have been noted for this gene. [provided by RefSeq]

Full Name

exostoses (multiple) 2

Research Area

Glycosyltransferase required for the biosynthesis of heparan-sulfate. The EXT1/EXT2 complex possesses substantially higher glycosyltransferase activity than EXT1 or EXT2 alone. Appears to be a tumor suppressor. Required for the exosomal release of SDCBP, CD63 and syndecan (PubMed:22660413).

Biological Process

Cell differentiation Source: Ensembl
Cellular polysaccharide biosynthetic process Source: BHF-UCL
Cellular response to fibroblast growth factor stimulus Source: Ensembl
Endochondral bone morphogenesis Source: Ensembl
Fluid transport Source: Ensembl
Gene expression Source: Ensembl
Glycosaminoglycan biosynthetic process Source: BHF-UCL
Heart contraction Source: Ensembl
Heparan sulfate proteoglycan biosynthetic process Source: BHF-UCL
Heparan sulfate proteoglycan biosynthetic process, polysaccharide chain biosynthetic process Source: BHF-UCL
Heparin biosynthetic process Source: Ensembl
Mesoderm formation Source: Ensembl
Multicellular organismal water homeostasis Source: Ensembl
Ossification Source: BHF-UCL
Protein N-linked glycosylation Source: Ensembl
Regulation of blood pressure Source: Ensembl
Signal transduction Source: ProtInc
Sodium ion homeostasis Source: Ensembl
Sulfation Source: Ensembl
Vasodilation Source: Ensembl

Cellular Location

Endoplasmic reticulum membrane; Golgi apparatus membrane. The EXT1/EXT2 complex is localized in the Golgi apparatus.

Involvement in disease

Hereditary multiple exostoses 2 (EXT2):
EXT is a genetically heterogeneous bone disorder caused by genes segregating on human chromosomes 8, 11, and 19 and designated EXT1, EXT2 and EXT3 respectively. EXT is a dominantly inherited skeletal disorder primarily affecting endochondral bone during growth. The disease is characterized by formation of numerous cartilage-capped, benign bone tumors (osteocartilaginous exostoses or osteochondromas) that are often accompanied by skeletal deformities and short stature. In a small percentage of cases exostoses have exhibited malignant transformation resulting in an osteosarcoma or chondrosarcoma. Osteochondromas development can also occur as a sporadic event.
Potocki-Shaffer syndrome (POSHS):
A syndrome characterized by foramina parietalia permagna, multiple exostoses, and craniofacial dysostosis and mental retardation in some cases.
Seizures, scoliosis, and macrocephaly/microcephaly syndrome (SSMS):
An autosomal recessive syndrome characterized by seizures, intellectual disability, hypotonia, scoliosis, macrocephaly, hypertelorism and renal dysfunction.

Topology

Cytoplasmic: 1-25
Helical: 26-46
Lumenal: 47-718