CD24 induces localization of beta1 integrin to lipid raft domains.
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.
Runz
Steffen
S
Tumor Immunology Programme, D010, German Cancer Research Center, Im Neuenheimer Feld 580, D-69120 Heidelberg, Germany.
Mierke
Claudia T
CT
Joumaa
Safwan
S
Behrens
Jürgen
J
Fabry
Ben
B
Altevogt
Peter
P
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
D051927:CD24 Antigen; C497889:CD24 protein, human; D019012:Integrin beta1; D021122:Protein Subunits