cdg 1

TGFBI is an RGD-containing protein that binds to type I, II and IV collagens. The RGD motif is found in many extracellular matrix proteins modulating cell adhesion and serves as a ligand recognition sequence for several integrins. TGFBI plays a role in cell-collagen interactions and may be involved in endochondral bone formation in cartilage. TGFBI is induced by transforming growth factor-beta and acts to inhibit cell adhesion. Mutations in TGFBI are associated with multiple types of corneal dystrophy. TGFBI can bind to type I, II, and IV collagens. This adhesion protein may play an important role in cell-collagen interactions. In cartilage, TGFBI may be involved in endochondral bone formation. Loss of the TGFBI is sufficient to induce specific resistance.

Phosphomannomutase 2, also known as PMM2 and CDG1, belongs to the eukaryotic PMM family. Phosphomannomutase 2 catalyzes the isomerization of mannose 6-phosphate to mannose 1-phosphate. Mannose 1-phosphate is a precursor to GDP-mannose necessary for the synthesis of dolichol-P-oligosaccharides. GDP-mannose can transfer its small sugar molecule called mannose to the growing oligosaccharide chain. Once the correct number of small sugar molecules are linked together to form the oligosaccharide, it can be attached to a protein. Phosphomannomutase 2 is also required for a number of critical mannosyl transfer reactions. Mutations in PMM2 gene have been shown to cause defects in the protein glycosylation pathway manifest as carbohydrate-deficient glycoprotein syndrome type I.