OMIM *154550
EC.5.3.1.8
Function
Involved in the synthesis of the GDP-mannose and dolichol-phosphate-mannose required for a number of critical mannosyl transfer reactions.
Catalytic activity
D-mannose 6-phosphate = D-fructose 6-phosphate.
Cofactor
Binds 1 zinc ion per subunit By similarity.
Pathway
Nucleotide-sugar biosynthesis; GDP-alpha-D-mannose biosynthesis; alpha-D-mannose 1-phosphate from D-fructose 6-phosphate: step 1/2.
Subcellular location
Cytoplasm Probable.
Tissue specificity
Expressed in all tissues, but more abundant in heart, brain and skeletal muscle.
Involvement in disease
Defects in MPI are the cause of congenital disorder of glycosylation type 1B (CDG1B) [MIM:602579]; also known as carbohydrate-deficient glycoprotein syndrome type Ib (CDGS1B). Congenital disorders of glycosylation are metabolic deficiencies in glycoprotein biosynthesis that usually cause severe mental and psychomotor retardation. They are characterized by under-glycosylated serum glycoproteins. CDG1B is clinically characterized by protein-losing enteropathy. Ref.2 Ref.8 Ref.9 Ref.10 Ref.11 Ref.12 Ref.13
Sequence similarities
Belongs to the mannose-6-phosphate isomerase type 1 family.
