tetano
Editor, Senior Moderator
J Biol Chem. 2016 Feb 19. pii: jbc.M115.710533. [Epub ahead of print]
[h=1]Synchrotron Infrared and Deep UV Fluorescent Microspectroscopy Study of PB1-F2 β-Aggregated Structures in Influenza A Virus-Infected Cells.[/h] Chevalier C[SUP]1[/SUP], Le Goffic R[SUP]2[/SUP], Jamme F[SUP]3[/SUP], Leymarie O[SUP]2[/SUP], R?fr?giers M[SUP]3[/SUP], Delmas B[SUP]2[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] PB1-F2 is a virulence factor of Influenza A Virus (IAV) whose functions remain misunderstood. The different roles of PB1-F2 may be linked to its structural polymorphism and to its propensity to assemble into oligomers and amyloid fibers in the vicinity of the membrane of IAV-infected cells. Here, we monitored the impact of PB1-F2 on the biochemical composition and protein structures of human epithelial pulmonary cells (A549) and monocytic cells (U937) upon IAV infection using synchrotron Fourier-transform infrared (FTIR) and deep UV (DUV) microscopies at the single-cell level. Cells were infected with a wild-type IAV and its PB1-F2 knock-out mutant for analyses at different times post-infection (pi). IR spectra were recorded in each condition and processed to evaluate the change in the component band of the spectra corresponding to the amide I (secondary structure) and the CH stretching region (membrane). The IR spectra analysis revealed that expression of PB1-F2 in U937 cells, but not in A549 cells, results in the presence of a specific beta-aggregate signature. Furthermore, the lipid membrane composition of U937 cells expressing PB1-F2 was also altered in a cell-type dependent manner. Using DUV microscopy and taking advantage of the high content of tryptophan residues in the sequence of PB1-F2 (5/90 aa), we showed that the increase of the auto-fluorescent signal recorded in monocytic cells could be correlated with the IR detection of beta-aggregates. Altogether, our results constitute an important step forward in the understanding of the cell-type dependent function of PB1-F2.
Copyright ? 2016, The American Society for Biochemistry and Molecular Biology.
[h=4]KEYWORDS:[/h] Fourier transform IR (FTIR); amyloid; fluorescence imaging; influenza virus; membrane; microscopy; oligomerization; synchrotron radiation experiment
PMID: 26896002 [PubMed - as supplied by publisher] Free full text
[h=1]Synchrotron Infrared and Deep UV Fluorescent Microspectroscopy Study of PB1-F2 β-Aggregated Structures in Influenza A Virus-Infected Cells.[/h] Chevalier C[SUP]1[/SUP], Le Goffic R[SUP]2[/SUP], Jamme F[SUP]3[/SUP], Leymarie O[SUP]2[/SUP], R?fr?giers M[SUP]3[/SUP], Delmas B[SUP]2[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] PB1-F2 is a virulence factor of Influenza A Virus (IAV) whose functions remain misunderstood. The different roles of PB1-F2 may be linked to its structural polymorphism and to its propensity to assemble into oligomers and amyloid fibers in the vicinity of the membrane of IAV-infected cells. Here, we monitored the impact of PB1-F2 on the biochemical composition and protein structures of human epithelial pulmonary cells (A549) and monocytic cells (U937) upon IAV infection using synchrotron Fourier-transform infrared (FTIR) and deep UV (DUV) microscopies at the single-cell level. Cells were infected with a wild-type IAV and its PB1-F2 knock-out mutant for analyses at different times post-infection (pi). IR spectra were recorded in each condition and processed to evaluate the change in the component band of the spectra corresponding to the amide I (secondary structure) and the CH stretching region (membrane). The IR spectra analysis revealed that expression of PB1-F2 in U937 cells, but not in A549 cells, results in the presence of a specific beta-aggregate signature. Furthermore, the lipid membrane composition of U937 cells expressing PB1-F2 was also altered in a cell-type dependent manner. Using DUV microscopy and taking advantage of the high content of tryptophan residues in the sequence of PB1-F2 (5/90 aa), we showed that the increase of the auto-fluorescent signal recorded in monocytic cells could be correlated with the IR detection of beta-aggregates. Altogether, our results constitute an important step forward in the understanding of the cell-type dependent function of PB1-F2.
Copyright ? 2016, The American Society for Biochemistry and Molecular Biology.
[h=4]KEYWORDS:[/h] Fourier transform IR (FTIR); amyloid; fluorescence imaging; influenza virus; membrane; microscopy; oligomerization; synchrotron radiation experiment
PMID: 26896002 [PubMed - as supplied by publisher] Free full text