NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.
Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.
An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Grafting Segments from the Extracellular Surface of CCR5 onto a Bacteriorhodopsin Transmembrane Scaffold Confers HIV-1 Corcceptor Activity
Published
Author(s)
N G. Abdulaev, T T. Strassmaier, T Ngo, R W. Chen, H Lueke, D D. Oprian, K D. Ridge
Abstract
The G-protein coupled receptor CCR5 binds three distinct B-chemokines on the solvent exposed segments of the extracellular surface. This same region of CCr5 also interacts with certain macrophage-tropic strains of HIV-1. To investigate structural features of CCR5 that contribute toward HIV-1 coreceptor activity, the amino-terminal and extracellular loop segments of CCR5 were linked to form contiguous polypeptides or grafted onto a seven transmembrane helix bacteriorhodopsin (bR) scaffold either singly, or in combination, to produce a series of CCR5/bR chimeras. The CCR5 extracellular surface polypeptides and CCR5/bR chimeras were expressed in E. coli or COS-1 cells and tested for cell surface expression, all trans retinal binding, and/or CD4 dependent env mediated coreceptor activity. The results show that some the CCR5/bR chimeras are transported to the cell surface and form a bR-like chromophore will all-trans retinal. Further, env mediated cell fusion assays identified structural features in the amino-terminal region of the CCR5/bR chimeras that are sufficient for interaction with JRFL env. Mutations at tyrosine rediuses 10 and 14 in the amino-terminal segment of CCR5, persumed tyrosyl sulfation sites, markedly reduced coreceptor activity. A chimera containing the entire extracellular surface of CCR5 grafted onto the bR scaffold exhibited all-trans retinal dependent coreceptor activity. Thus, the approach of using bR as a seven transmembrane helix scaffold may offer an alternative strategy for studying specific receptor-ligand/viral interactions in other G-protein coupled receptors.
Abdulaev, N.
, Strassmaier, T.
, Ngo, T.
, Chen, R.
, Lueke, H.
, Oprian, D.
and Ridge, K.
(2002),
Grafting Segments from the Extracellular Surface of CCR5 onto a Bacteriorhodopsin Transmembrane Scaffold Confers HIV-1 Corcceptor Activity, Structure
(Accessed October 1, 2025)