title: EB1 contributes to proper front-to-back polarity in neutrophil-like HL-60 cells.
abstract: Directed migration of leukocytes towards a chemotactic source is largely dependent on coordinated actin cytoskeleton functions that provide the driving forces at the cell front and enable contractility at the rear. In contrast to the force-generating properties of the actin cytoskeleton, the microtubule network assumes a regulatory function in balancing front-to-back polarity. In migrating neutrophils, microtubules are mostly concentrated at the cell rear, and previously published work suggested that microtubules are stabilized and kept in place by a mechanism involving Cdc42, WASP, CD11b, and the end-binding protein 1 (EB1). EB1, as a microtubule plus-end tracking protein (+TIP), is a potential candidate to bridge the gap between microtubule and actomyosin dynamics. After knockdown of EB1 in neutrophil-like HL-60 cells, both directionality and straightness of migration while moving through 3D collagen gels are impaired. An increased number of lateral protrusions are observed in EB1-knockdown cells, indicating an inability to balance cell polarity in the absence of EB1. Moreover, in EB1-deficient cells, substrate adhesion on fibrinogen-coated surfaces is significantly reduced. EB1-knockdown cells show significant changes in levels of GEF-H1, a microtubule-associated guanine nucleotide exchange factor that links microtubule integrity to RhoA-dependent regulation of the actin cytoskeleton, suggesting that GEF-H1 might constitute one element of the microtubule-actin crosstalk in migrating leukocytes.
authors.affiliation: Department of Cell Biology (Anatomy III), Biomedical Center, LMU Munich, 82152 Planegg-Martinsried, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Samereier
authors.affiliation: Department of Cell Biology (Anatomy III), Biomedical Center, LMU Munich, 82152 Planegg-Martinsried, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Schleicher
authors.affiliation: Department of Cell Biology (Anatomy III), Biomedical Center, LMU Munich, 82152 Planegg-Martinsried, Germany.
authors.forename: Heike
authors.initials: H
authors.lastname: Roth
authors.affiliation: Department of Cardiovascular Physiology and Pathophysiology, Walter Brendel Centre of Experimental Medicine, Biomedical Center, LMU Munich, 82152 Planegg-Martinsried, Germany.
authors.forename: Doris
authors.initials: D
authors.lastname: Brechtefeld
authors.affiliation: Department of Cardiovascular Physiology and Pathophysiology, Walter Brendel Centre of Experimental Medicine, Biomedical Center, LMU Munich, 82152 Planegg-Martinsried, Germany.
authors.forename: Barbara
authors.initials: B
authors.lastname: Walzog
authors.affiliation: Department of Cell Biology (Anatomy III), Biomedical Center, LMU Munich, 82152 Planegg-Martinsried, Germany. Electronic address: amueller@lrz.uni-muenchen.de.
authors.forename: Annette
authors.initials: A
authors.lastname: Müller-Taubenberger
mesh_terms: D016764:Cell Polarity / Q000502:physiology; D002634:Chemotaxis, Leukocyte / Q000502:physiology; D055785:Gene Knockdown Techniques; D018922:HL-60 Cells; D006801:Humans; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D008870:Microtubules / Q000502:physiology; D009504:Neutrophils / Q000166:cytology* / Q000378:metabolism*; D014162:Transfection
chemical_list: C500985:MAPRE1 protein, human; D008869:Microtubule-Associated Proteins
keywords: Chemotaxis; EB1; HL-60; Microtubules; Migration