title: Role of cation independent mannose 6-phosphate receptor protein in sorting and intracellular trafficking of lysosomal enzymes in chicken embryonic fibroblast (CEF) cells.
abstract: Delivery of soluble lysosomal proteins to the lysosomes is dependent primarily on the mannose 6-phosphate receptors (MPRs) in mammals. However, in non-mammalian cells the role of MPR300 in sorting and trafficking of acid hydrolases to lysosomes is not fully understood till now. In this paper, we tested the role of MPR300 in sorting and trafficking of lysosomal enzymes in CEF cells using a small interfering RNA (siRNA) technology. Inactivation of MPR300 resulted in the secretion of large amounts of newly synthesized hydrolases into the medium and also inhibited the endocytosis of mannose 6-phospharylated ligands. Knockdown of MPR300 in CEF cells results in missorting of fucosidase and arylsulfatse A enzymes into the medium. The results indicated that the MPR300 in CEF cells plays a key role in sorting and trafficking of these soluble hydrolases.
authors.affiliation: Protein Biochemistry and Molecular biology laboratory, Department of Biochemistry, University of Hyderabad, Hyderabad, 500 046, India.
authors.forename: Sivaramakrishna
authors.initials: S
authors.lastname: Yadavalli
authors.forename: Siva Kumar
authors.initials: SK
authors.lastname: Nadimpalli
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002412:Cations; D002553:Cerebroside-Sulfatase / Q000378:metabolism; D002642:Chick Embryo; D015536:Down-Regulation; D005347:Fibroblasts / Q000201:enzymology*; D020868:Gene Silencing; D006867:Hydrolases / Q000378:metabolism; D042541:Intracellular Space / Q000378:metabolism*; D008024:Ligands; D008247:Lysosomes / Q000201:enzymology*; D010766:Phosphorylation; D021381:Protein Transport; D011506:Proteins / Q000378:metabolism*; D017527:Receptor, IGF Type 2 / Q000378:metabolism*; D005644:alpha-L-Fucosidase / Q000378:metabolism
chemical_list: D002412:Cations; D008024:Ligands; D011506:Proteins; D017527:Receptor, IGF Type 2; C018589:lysosomal proteins; D006867:Hydrolases; D002553:Cerebroside-Sulfatase; D005644:alpha-L-Fucosidase