Products (Ext1 and Ext2) of tumour suppressor genes involved in the expression of proteoglycans on the cell surface and in extracellular matrix. The two proteins (746 aa, 718 aa) form a hetero-oligomeric complex with glycosyltransferase activity that accumulates in the Golgi. Mutations in Ext1 or Ext2 are associated with multiple exostes type 1 or 2 respectively (autosomal dominant disorders in which there are multiple projections of bone capped by cartilage (exostoses), particularly, but not exclusively, in metaphyses of long bones). May also regulate the hedgehog signalling pathway.
Subjects: Medicine and Health.