Oligomerization of the Nef protein from human immunodeficiency virus (HIV) type 1

Abstract

The nef genes, derived from two different human immunodeficiency-virus-type-1 (HIV-1) strains, were expressed in procaryotic cells (Escherichia coli) and in eucaryotic cells (insect cells infected with nef-containing baculovirus). The oligomerization of recombinant Nef protein was studied by NMR spectroscopy and immunoblotting under various experimental conditions. 1H-NMR spectroscopy shows that native folded protein has the tendency to polymerize under low-salt conditions. These oligomers become covalently linked by disulfide bonds after decreasing the reduction potential, a process which is fully reversible. Cross-linking studies with bis(sulfo-succinimidyl)suberate and alkylation with iodoacetic acid under non-reducing and reducing conditions document for the first time that Nef can also form homomeric structures including monomers, dimers, trimers and tetramers in cell lysates and intact cells. We found disulfide-linked as well as non-covalently associated oligomers. Since the Nef molecules are not exclusively found in the cytoplasm of HIV infected cells and since the reduced glutathione concentration in lymphocytes of virus infected persons is known to be unusually low, it might be possible that these Nef oligomers have a biological function in vivo as well

Clustered localization of oligomeric Nef protein of human immunodeficiency virus type 1 on the cell surface

“…This coding region is located at the 3' end of HIV-1 with the Acnef-0 baculorecombinant virus [11] and finally purified genome, partially overlapping the 3' long terminal repeat with anti-Nef mAb-conjugated Affi-Gel column (unpublished). The (LTR).…”

“…HIV-1 bacterial and eukaryotic systems form oligomers [11], but Nef, derived from baculosystem and from cells infected with there is no information about the oligomerization of Nef in HIV-I, formed homomeric monomers, dimers, trimers, and HIV-l-infected T cells. To clarify the mechanism of Nef-defurther polymers.…”

Signaling but not trafficking function of HIV-1 protein Nef is essential for Nef-induced defects in human intrathymic T-cell development

“…Nef oligomers have been reported by several groups, 43,44 but their importance in Nef activities has not been elucidated yet. In the Nef oligomers, Asp123 is interacting with the conserved di-arginine motif Arg105Arg106 of another protomer.…”

Characterization and molecular basis of the oligomeric structure of HIV‐1 Nef protein

“…Oligomerization of HIV-1 Nef expressed in bacteria and eucaryotic cells has first been reported by Kienzle et al~1993!. Homomeric Nef dimers, trimers, and higher oligomers were subsequently reported on the surface of infected HeLa CD4ϩ cells~Fujii et al, 1996!.…”