title: Crucial role for the LSP1-myosin1e bimolecular complex in the regulation of Fcγ receptor-driven phagocytosis.
abstract: Actin cytoskeleton remodeling is fundamental for Fcγ receptor-driven phagocytosis. In this study, we find that the leukocyte-specific protein 1 (LSP1) localizes to nascent phagocytic cups during Fcγ receptor-mediated phagocytosis, where it displays the same spatial and temporal distribution as the actin cytoskeleton. Down-regulation of LSP1 severely reduces the phagocytic activity of macrophages, clearly demonstrating a crucial role for this protein in Fcγ receptor-mediated phagocytosis. We also find that LSP1 binds to the class I molecular motor myosin1e. LSP1 interacts with the SH3 domain of myosin1e, and the localization and dynamics of both proteins in nascent phagocytic cups mirror those of actin. Furthermore, inhibition of LSP1-myosin1e and LSP1-actin interactions profoundly impairs pseudopodial formation around opsonized targets and their subsequent internalization. Thus the LSP1-myosin1e bimolecular complex plays a pivotal role in the regulation of actin cytoskeleton remodeling during Fcγ receptor-driven phagocytosis.
authors.affiliation: Institute of Biomedical Engineering, Department of Cell Biology, Applied Ecology, D-52074 Aachen, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Maxeiner
authors.affiliation: Institute of Biomedical Engineering, Department of Cell Biology, Applied Ecology, D-52074 Aachen, Germany.
authors.forename: Nian
authors.initials: N
authors.lastname: Shi
authors.affiliation: Institute of Biomedical Engineering, Department of Cell Biology, Applied Ecology, D-52074 Aachen, Germany.
authors.forename: Carmen
authors.initials: C
authors.lastname: Schalla
authors.affiliation: Institute of Biomedical Engineering, Department of Cell Biology, Applied Ecology, D-52074 Aachen, Germany.
authors.forename: Guelcan
authors.initials: G
authors.lastname: Aydin
authors.affiliation: Electron Microscopy Facility, Uniklinik RWTH Aachen, Applied Ecology, D-52074 Aachen, Germany.
authors.forename: Mareike
authors.initials: M
authors.lastname: Hoss
authors.affiliation: Fraunhofer Institute for Molecular Biology and Applied Ecology, D-52074 Aachen, Germany.
authors.forename: Simon
authors.initials: S
authors.lastname: Vogel
authors.affiliation: Institute of Biomedical Engineering, Department of Cell Biology, Applied Ecology, D-52074 Aachen, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Zenke
authors.affiliation: Institute of Biomedical Engineering, Department of Cell Biology, Applied Ecology, D-52074 Aachen, Germany antonio.sechi@rwth-aachen.de.
authors.forename: Antonio S
authors.initials: AS
authors.lastname: Sechi
mesh_terms: D000818:Animals; D002135:Calcium-Binding Proteins / Q000502:physiology*; D051379:Mice; D008840:Microfilament Proteins; D024461:Myosin Type I; D009218:Myosins / Q000502:physiology*; D041681:NIH 3T3 Cells; D010587:Phagocytosis; D021381:Protein Transport; D017452:Receptors, IgG / Q000502:physiology*
chemical_list: D002135:Calcium-Binding Proteins; C057701:Lsp1 protein, mouse; D008840:Microfilament Proteins; D017452:Receptors, IgG; C505821:Myo1e protein, mouse; D024461:Myosin Type I; D009218:Myosins