title: Mapping the laminin-binding and adhesive domain of the cell surface-associated Hlp/LBP protein from Mycobacterium leprae.
abstract: Binding of Mycobacterium leprae to and invasion of Schwann cells (SC) represent a crucial step that initiates nerve damage in leprosy. We and others have described that M. leprae colonization of the peripheral nerve system may be mediated in part by a surface-exposed histone-like protein (Hlp), characterized as a laminin-binding protein (LBP). Hlp/LBP has also been shown to play a role in the binding of mycobacteria to alveolar epithelial cells and macrophages. In the present study we report that M. leprae expresses Hlp/LBP protein during the course of human infection. Additionally, we analyzed the interaction of Hlp/LBP with the extracellular matrix and host cell surface. We show that Hlp/LBP, besides laminin, also binds heparin and heparan sulfate. Testing truncated recombinant Hlp molecules corresponding to the N-terminal (rHlp-N) and the C-terminal (rHlp-C) domains of the protein, we established that interaction of Hlp/LBP with laminin-2 and heparin is mainly mediated by the C-terminal domain of the protein. Moreover, the same domain was found to be involved in Hlp/LBP-mediating bacterial binding to human SC. Finally, evidence is shown suggesting that M. leprae produces a post-translationally modified Hlp/LBP containing methyllysine residues. Methylation of the lysine residues, however, seems not to affect the adhesive properties of Hlp/LBP. Taken together, our observations reinforce the involvement of Hlp/LBP as an adhesin in mycobacterial infections and define its highly positive C-terminal region as the major adhesive domain of this protein.
authors.affiliation: Laboratory of Cellular Microbiology, Instituto Oswaldo Cruz, Fiocruz, RJ 21045-900, Brazil.
authors.forename: Cristiana
authors.initials: C
authors.lastname: Soares de Lima
authors.forename: Laurence
authors.initials: L
authors.lastname: Zulianello
authors.forename: Maria Angela de Melo
authors.initials: MA
authors.lastname: Marques
authors.forename: Heejin
authors.initials: H
authors.lastname: Kim
authors.forename: Michelle Iespa
authors.initials: MI
authors.lastname: Portugal
authors.forename: Sérgio Luiz
authors.initials: SL
authors.lastname: Antunes
authors.forename: Franco Dante
authors.initials: FD
authors.lastname: Menozzi
authors.forename: Tom Henricus Maria
authors.initials: TH
authors.lastname: Ottenhoff
authors.forename: Patrick Joseph
authors.initials: PJ
authors.lastname: Brennan
authors.forename: Maria Cristina Vidal
authors.initials: MC
authors.lastname: Pessolani
mesh_terms: D018829:Adhesins, Bacterial / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D015870:Gene Expression; D006493:Heparin / Q000378:metabolism; D006497:Heparan Sulfate / Q000378:metabolism; D006801:Humans; D007797:Laminin / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins / Q000138:chemical synthesis / Q000235:genetics / Q000378:metabolism*; D009166:Mycobacterium leprae / Q000502:physiology*; D025941:Protein Interaction Mapping; D017434:Protein Structure, Tertiary; D012583:Schwann Cells / Q000382:microbiology; D017384:Sequence Deletion
chemical_list: D018829:Adhesins, Bacterial; D001426:Bacterial Proteins; D006493:Heparin; D006497:Heparan Sulfate; D007797:Laminin; D008565:Membrane Proteins