title: [Disorders of sphingolipid activator proteins].
abstract: Small-molecular nonenzymatic glycoproteins are necessary for degradation of sphingolipids in lysosomes. GM2 activator encoded by a gene on chromosome 5 is essential for hydrolysis of ganglioside GM2 and its asialo derivative. Mutations of this gene cause Tay-Sachs disease-like clinical phenotype (GM2-gangliosidosis AB variant). Another gene on chromosome 10 codes for a protein called prosaposin, which is then processed to four related but independent activator proteins; saposin A, B, C, and D. These five proteins show different molecular functions, and their mutations cause diseases with prosaposin deficiency (clinically similar to Gaucher disease type 2), and saposin C deficiency (clinically similar to Gaucher disease type 3). They are rare genetic disorders, but provide information about molecular events between the enzyme and substrate in lysosomes.
authors.affiliation: Tokyo Metropolitan Institute of Medical Science.
authors.forename: Y
authors.initials: Y
authors.lastname: Suzuki
mesh_terms: D005678:G(M2) Ganglioside / Q000378:metabolism; D006023:Glycoproteins / Q000172:deficiency / Q000235:genetics* / Q000502:physiology; D006801:Humans; D008247:Lysosomes / Q000378:metabolism; D009154:Mutation; D011498:Protein Precursors / Q000172:deficiency / Q000235:genetics*; D049231:Saposins; D049128:Sphingolipid Activator Proteins; D013107:Sphingolipids / Q000378:metabolism
chemical_list: D006023:Glycoproteins; C483345:PSAP protein, human; D011498:Protein Precursors; D049231:Saposins; D049128:Sphingolipid Activator Proteins; D013107:Sphingolipids; D005678:G(M2) Ganglioside