title: Translation initiation factors and active sites of protein synthesis co-localize at the leading edge of migrating fibroblasts.
abstract: Cell migration is a highly controlled essential cellular process, often dysregulated in tumour cells, dynamically controlled by the architecture of the cell. Studies involving cellular fractionation and microarray profiling have previously identified functionally distinct mRNA populations specific to cellular organelles and architectural compartments. However, the interaction between the translational machinery itself and cellular structures is relatively unexplored. To help understand the role for the compartmentalization and localized protein synthesis in cell migration, we have used scanning confocal microscopy, immunofluorescence and a novel ribopuromycylation method to visualize translating ribosomes. In the present study we show that eIFs (eukaryotic initiation factors) localize to the leading edge of migrating MRC5 fibroblasts in a process dependent on TGN (trans-Golgi network) to plasma membrane vesicle transport. We show that eIF4E and eIF4GI are associated with the Golgi apparatus and membrane microdomains, and that a proportion of these proteins co-localize to sites of active translation at the leading edge of migrating cells.
authors.affiliation: Department of Biochemistry, School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK.
authors.forename: Mark
authors.initials: M
authors.lastname: Willett
authors.forename: Michele
authors.initials: M
authors.lastname: Brocard
authors.forename: Alexandre
authors.initials: A
authors.lastname: Davide
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Morley
mesh_terms: D020134:Catalytic Domain; D002465:Cell Movement; D002478:Cells, Cultured; D039561:Eukaryotic Initiation Factor-4E / Q000378:metabolism*; D039603:Eukaryotic Initiation Factor-4G / Q000378:metabolism*; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism*; D031541:Fluorescence Resonance Energy Transfer; D005455:Fluorescent Antibody Technique; D006056:Golgi Apparatus / Q000378:metabolism*; D006801:Humans; D007124:Immunoenzyme Techniques; D021962:Membrane Microdomains / Q000378:metabolism; D014176:Protein Biosynthesis; D012270:Ribosomes / Q000378:metabolism*; D021601:trans-Golgi Network
chemical_list: C113920:EIF4G1 protein, human; D039561:Eukaryotic Initiation Factor-4E; D039603:Eukaryotic Initiation Factor-4G