title: Deciphering the complex three-way interaction between the non-integrin laminin receptor, galectin-3 and Neisseria meningitidis.
abstract: The non-integrin laminin receptor (LAMR1/RPSA) and galectin-3 (Gal-3) are multi-functional host molecules with roles in diverse pathological processes, particularly of infectious or oncogenic origins. Using bimolecular fluorescence complementation and confocal imaging, we demonstrate that the two proteins homo- and heterodimerize, and that each isotype forms a distinct cell surface population. We present evidence that the 37 kDa form of LAMR1 (37LRP) is the precursor of the previously described 67 kDa laminin receptor (67LR), whereas the heterodimer represents an entity that is distinct from this molecule. Site-directed mutagenesis confirmed that the single cysteine (C(173)) of Gal-3 or lysine (K(166)) of LAMR1 are critical for heterodimerization. Recombinant Gal-3, expressed in normally Gal-3-deficient N2a cells, dimerized with endogenous LAMR1 and led to a significantly increased number of internalized bacteria (Neisseria meningitidis), confirming the role of Gal-3 in bacterial invasion. Contact-dependent cross-linking determined that, in common with LAMR1, Gal-3 binds the meningococcal secretin PilQ, in addition to the major pilin PilE. This study adds significant new mechanistic insights into the bacterial-host cell interaction by clarifying the nature, role and bacterial ligands of LAMR1 and Gal-3 isotypes during colonization.
authors.affiliation: School of Life Sciences, Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
authors.forename: Fulwah
authors.initials: F
authors.lastname: Alqahtani
authors.affiliation: School of Life Sciences, Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK jafar.mahdavi@nottingham.ac.uk.
authors.forename: Jafar
authors.initials: J
authors.lastname: Mahdavi
authors.affiliation: School of Life Sciences, Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
authors.forename: Lee M
authors.initials: LM
authors.lastname: Wheldon
authors.affiliation: School of Life Sciences, Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
authors.forename: Matthew
authors.initials: M
authors.lastname: Vassey
authors.affiliation: Department of Chemistry, University of Dicle, 21280 Diyarbakir, Turkey.
authors.forename: Necmettin
authors.initials: N
authors.lastname: Pirinccioglu
authors.affiliation: School of Life Sciences, Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
authors.forename: Pierre-Joseph
authors.initials: PJ
authors.lastname: Royer
authors.affiliation: School of Life Sciences, Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
authors.forename: Suzan M
authors.initials: SM
authors.lastname: Qarani
authors.affiliation: School of Life Sciences, Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
authors.forename: Shaun
authors.initials: S
authors.lastname: Morroll
authors.affiliation: School of Life Sciences, Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
authors.forename: Jeroen
authors.initials: J
authors.lastname: Stoof
authors.affiliation: School of Life Sciences, Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
authors.forename: Nicholas D
authors.initials: ND
authors.lastname: Holliday
authors.affiliation: School of Life Sciences, Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
authors.forename: Siew Y
authors.initials: SY
authors.lastname: Teo
authors.affiliation: School of Life Sciences, Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
authors.forename: Neil J
authors.initials: NJ
authors.lastname: Oldfield
authors.affiliation: School of Life Sciences, Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK karl.wooldridge@nottingham.ac.uk.
authors.forename: Karl G
authors.initials: KG
authors.lastname: Wooldridge
authors.affiliation: School of Life Sciences, Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
authors.forename: Dlawer A A
authors.initials: DA
authors.lastname: Ala'Aldeen
mesh_terms: D000818:Animals; D019556:COS Cells; D002462:Cell Membrane / Q000378:metabolism; D002522:Chlorocebus aethiops; D003432:Cross-Linking Reagents / Q000737:chemistry; D042783:Endothelial Cells / Q000378:metabolism* / Q000382:microbiology*; D037502:Galectin 3 / Q000378:metabolism*; D005786:Gene Expression Regulation; D006801:Humans; D006860:Hydrogen Bonding; D016023:Integrins / Q000378:metabolism; D007785:Lactose / Q000737:chemistry; D008024:Ligands; D051379:Mice; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D008958:Models, Molecular; D008968:Molecular Conformation; D016297:Mutagenesis, Site-Directed; D009345:Neisseria meningitidis / Q000378:metabolism*; D055503:Protein Multimerization; D017474:Receptors, Laminin / Q000378:metabolism*
chemical_list: D003432:Cross-Linking Reagents; D037502:Galectin 3; D016023:Integrins; D008024:Ligands; D017474:Receptors, Laminin; D007785:Lactose
keywords: 37LRP; 67LR; LAMR1; Neisseria meningitidis; RPSA; galectin-3