title: Flotillins are involved in the polarization of primitive and mature hematopoietic cells.
abstract: BACKGROUND
  Migration of mature and immature leukocytes in response to chemokines is not only essential during inflammation and host defense, but also during development of the hematopoietic system. Many molecules implicated in migratory polarity show uniform cellular distribution under non-activated conditions, but acquire a polarized localization upon exposure to migratory cues.
  
  
  RESULTS
  Here, we present evidence that raft-associated endocytic proteins (flotillins) are pre-assembled in lymphoid, myeloid and primitive hematopoietic cells and accumulate in the uropod during migration. Furthermore, flotillins display a polarized distribution during immunological synapse formation. Employing the membrane lipid-order sensitive probe Laurdan, we show that flotillin accumulation in the immunological synapse is concomittant with membrane ordering in these regions.
  
  
  CONCLUSIONS
  Together with the observation that flotillin polarization does not occur in other polarized cell types such as polarized epithelial cells, our results suggest a specific role for flotillins in hematopoietic cell polarization. Based on our results, we propose that in hematopoietic cells, flotillins provide intrinsic cues that govern segregation of certain microdomain-associated molecules during immune cell polarization.
authors.affiliation: Systems and Cell Biology of Neurodegeneration, Department of Psychiatry Research, University of Zurich, Zurich, Switzerland. rajendran@bli.uzh.ch
authors.forename: Lawrence
authors.initials: L
authors.lastname: Rajendran
authors.forename: Julia
authors.initials: J
authors.lastname: Beckmann
authors.forename: Astrid
authors.initials: A
authors.lastname: Magenau
authors.forename: Eva-Maria
authors.initials: EM
authors.lastname: Boneberg
authors.forename: Katharina
authors.initials: K
authors.lastname: Gaus
authors.forename: Antonella
authors.initials: A
authors.lastname: Viola
authors.forename: Bernd
authors.initials: B
authors.lastname: Giebel
authors.forename: Harald
authors.initials: H
authors.lastname: Illges
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D018952:Antigens, CD34 / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D016764:Cell Polarity / Q000187:drug effects; D054377:Chemokine CXCL12 / Q000494:pharmacology; D003599:Cytoskeleton / Q000187:drug effects / Q000378:metabolism; D004285:Dogs; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000187:drug effects; D006801:Humans; D054992:Immunological Synapses / Q000187:drug effects / Q000378:metabolism; D021962:Membrane Microdomains / Q000187:drug effects / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism*; D009000:Monocytes / Q000166:cytology / Q000187:drug effects; D021381:Protein Transport / Q000187:drug effects; D011554:Pseudopodia / Q000187:drug effects / Q000378:metabolism; D013601:T-Lymphocytes / Q000166:cytology / Q000187:drug effects
chemical_list: D000199:Actins; D018952:Antigens, CD34; D015415:Biomarkers; D054377:Chemokine CXCL12; D008565:Membrane Proteins; C106354:flotillins; D016178:Granulocyte-Macrophage Colony-Stimulating Factor