title: CD24 induces localization of beta1 integrin to lipid raft domains.
abstract: The expression of the glycosyl phosphatidylinositol (GPI)-anchored protein CD24 correlates with poor prognosis in a variety of carcinomas. However, little is known about the cellular mechanisms of the CD24-mediated effects. In this study, we present evidence that CD24 affects the lateral localization of beta1 integrin. Using stably CD24-transfected A125 and MDA-MB-435S carcinoma cells we show that CD24 augments beta1-dependent cell motility and stimulates transmigration and invasion across a monolayer of endothelial cells. Furthermore, as demonstrated by sucrose density gradient centrifugation and Western Blot analysis, CD24 recruits beta1 integrin into lipid raft domains. We suggest that CD24 acts as a gate-keeper for lipid rafts, thereby regulating the activity of integrins and other proteins.
authors.affiliation: Tumor Immunology Programme, D010, German Cancer Research Center, Im Neuenheimer Feld 580, D-69120 Heidelberg, Germany.
authors.forename: Steffen
authors.initials: S
authors.lastname: Runz
authors.forename: Claudia T
authors.initials: CT
authors.lastname: Mierke
authors.forename: Safwan
authors.initials: S
authors.lastname: Joumaa
authors.forename: Jürgen
authors.initials: J
authors.lastname: Behrens
authors.forename: Ben
authors.initials: B
authors.lastname: Fabry
authors.forename: Peter
authors.initials: P
authors.lastname: Altevogt
mesh_terms: D001943:Breast Neoplasms / Q000378:metabolism; D051927:CD24 Antigen / Q000378:metabolism*; D045744:Cell Line, Tumor; D005260:Female; D006801:Humans; D019012:Integrin beta1 / Q000032:analysis* / Q000276:immunology; D008175:Lung Neoplasms / Q000378:metabolism; D021962:Membrane Microdomains / Q000378:metabolism*; D021122:Protein Subunits / Q000032:analysis; D014162:Transfection
chemical_list: D051927:CD24 Antigen; C497889:CD24 protein, human; D019012:Integrin beta1; D021122:Protein Subunits