title: Interaction of PLP with GFP-MAL2 in the human oligodendroglial cell line HOG.
abstract: The velocity of the nerve impulse conduction of vertebrates relies on the myelin sheath, an electrically insulating layer that surrounds axons in both the central and peripheral nervous systems, enabling saltatory conduction of the action potential. Oligodendrocytes are the myelin-producing glial cells in the central nervous system. A deeper understanding of the molecular basis of myelination and, specifically, of the transport of myelin proteins, will contribute to the search of the aetiology of many dysmyelinating and demyelinating diseases, including multiple sclerosis. Recent investigations suggest that proteolipid protein (PLP), the major myelin protein, could reach myelin sheath by an indirect transport pathway, that is, a transcytotic route via the plasma membrane of the cell body. If PLP transport relies on a transcytotic process, it is reasonable to consider that this myelin protein could be associated with MAL2, a raft protein essential for transcytosis. In this study, carried out with the human oligodendrocytic cell line HOG, we show that PLP colocalized with green fluorescent protein (GFP)-MAL2 after internalization from the plasma membrane. In addition, both immunoprecipitation and immunofluorescence assays, indicated the existence of an interaction between GFP-MAL2 and PLP. Finally, ultrastructural studies demonstrated colocalization of GFP-MAL2 and PLP in vesicles and tubulovesicular structures. Taken together, these results prove for the first time the interaction of PLP and MAL2 in oligodendrocytic cells, supporting the transcytotic model of PLP transport previously suggested.
authors.affiliation: Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid/Consejo Superior de Investigaciones Científicas, Cantoblanco, Madrid, Spain.
authors.forename: Raquel
authors.initials: R
authors.lastname: Bello-Morales
authors.forename: Marta
authors.initials: M
authors.lastname: Pérez-Hernández
authors.forename: María Teresa
authors.initials: MT
authors.lastname: Rejas
authors.forename: Fuencisla
authors.initials: F
authors.lastname: Matesanz
authors.forename: Antonio
authors.initials: A
authors.lastname: Alcina
authors.forename: José Antonio
authors.initials: JA
authors.lastname: López-Guerrero
mesh_terms: D002460:Cell Line; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D015151:Immunoblotting; D047468:Immunoprecipitation; D046529:Microscopy, Electron, Transmission; D008856:Microscopy, Fluorescence; D018991:Myelin Proteolipid Protein / Q000235:genetics / Q000378:metabolism*; D062806:Myelin and Lymphocyte-Associated Proteolipid Proteins; D009836:Oligodendroglia / Q000378:metabolism* / Q000648:ultrastructure; D011485:Protein Binding; D011510:Proteolipids / Q000235:genetics / Q000378:metabolism*; D033921:Vesicular Transport Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: C438606:MAL2 protein, human; D018991:Myelin Proteolipid Protein; D062806:Myelin and Lymphocyte-Associated Proteolipid Proteins; D011510:Proteolipids; D033921:Vesicular Transport Proteins; D049452:Green Fluorescent Proteins