Premium
Membrane interactions and alignment of structures within the HIV‐1 Vpu cytoplasmic domain: effect of phosphorylation of serines 52 and 56
Author(s) -
Henklein Peter,
Kinder Rudolf,
Schubert Ulrich,
Bechinger Burkhard
Publication year - 2000
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(00)02060-3
Subject(s) - cytoplasm , membrane , chemistry , phosphorylation , conformational change , crystallography , context (archaeology) , helix (gastropod) , biophysics , amphiphile , membrane protein , stereochemistry , biochemistry , biology , paleontology , ecology , organic chemistry , snail , copolymer , polymer
The cytoplasmic domain of the HIV‐1 accessory protein Vpu is involved in the binding and degradation of the viral receptor CD4. In order to analyze previous structural models in the context of membrane environments, regions of Vpu CYTO incorporating particular conformational features have been synthesized and labelled with 15 N at selected backbone amides. Well‐oriented proton‐decoupled 15 N solid‐state NMR spectra with 15 N chemical shifts at the most upfield position indicate that the amphipathic helix within [ 15 N‐Leu 45]‐Vpu 27–57 strongly interacts with mechanically aligned POPC bilayers and adopts an orientation parallel to the membrane surface. No major changes in the topology of this membrane‐associated amphipathic helix were observed upon phosphorylation of serine residues 52 and 56, although this modification regulates biological function of Vpu. In contrast, [ 15 N‐Ala 62]‐Vpu 51–81 exhibits a pronounced 15 N chemical shift anisotropy.