title: Transmembrane peptides used to investigate the homo-oligomeric interface and binding hotspot of latent membrane protein 1.
abstract: Epstein-Barr virus (EBV), a human γ-herpesvirus, establishes lifelong infection by targeting the adaptive immune system of the host through memory B cells. Although normally benign, EBV contributes to lymphoid malignancies and lymphoproliferative syndromes in immunocompromised individuals. The viral oncoprotein latent membrane protein 1 (LMP-1) is essential for B lymphocyte immortalization by EBV. The constitutive signaling activity of LMP-1 is dependent on homo-oligomerization of its six-spanning hydrophobic transmembrane domain (TMD). However, the mechanism driving LMP-1 intermolecular interaction is poorly understood. Here, we show that the fifth transmembrane helix (TM5) of LMP-1 strongly self-associates, forming a homotrimeric complex mediated by a polar residue embedded in the membrane, D150. Replacement of this aspartic acid residue with alanine disrupts TM5 self-association in detergent micelles and bacterial cell membranes. A full-length LMP-1 variant harboring the D150A substitution is deficient in NFκB activation, supporting the key role of the fifth transmembrane helix in constitutive activation of signaling by this oncoprotein.
authors.affiliation: Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO 80309, USA.
authors.forename: Deanne W
authors.initials: DW
authors.lastname: Sammond
authors.forename: Catherine
authors.initials: C
authors.lastname: Joce
authors.forename: Ryan
authors.initials: R
authors.lastname: Takeshita
authors.forename: Sarah E
authors.initials: SE
authors.lastname: McQuate
authors.forename: Nilanjan
authors.initials: N
authors.lastname: Ghosh
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Martin
authors.forename: Hang
authors.initials: H
authors.lastname: Yin
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites; D001704:Biopolymers / Q000378:metabolism*; D015153:Blotting, Western; D002942:Circular Dichroism; D017931:DNA Primers; D004591:Electrophoresis, Polyacrylamide Gel; D056004:Molecular Dynamics Simulation; D008969:Molecular Sequence Data; D010455:Peptides / Q000378:metabolism*; D017354:Point Mutation; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D014461:Ultracentrifugation; D014763:Viral Matrix Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D001704:Biopolymers; D017931:DNA Primers; C037662:EBV-associated membrane antigen, Epstein-Barr virus; D010455:Peptides; D014763:Viral Matrix Proteins