PMID- 10383387
OWN - NLM
STAT- MEDLINE
DCOM- 19990727
LR  - 20190508
IS  - 0021-9258 (Print)
IS  - 0021-9258 (Linking)
VI  - 274
IP  - 27
DP  - 1999 Jul 2
TI  - Extracellular cysteines of CCR5 are required for chemokine binding, but
      dispensable for HIV-1 coreceptor activity.
PG  - 18902-8
AB  - CCR5 is the major coreceptor for macrophage-tropic human immunodeficiency virus
      type I (HIV-1). For most G-protein-coupled receptors that have been tested so
      far, the disulfide bonds linking together the extracellular loops (ECL) are
      required for maintaining the structural integrity necessary for ligand binding
      and receptor activation. A natural mutation affecting Cys20, which is thought to 
      form a disulfide bond with Cys269, has been described in various human
      populations, although the consequences of this mutation for CCR5 function are not
      known. Using site-directed mutagenesis, we mutated the four extracellular
      cysteines of CCR5 singly or in combination to investigate their role in
      maintaining the structural conformation of the receptor, its ligand binding and
      signal transduction properties, and its ability to function as a viral
      coreceptor. Alanine substitution of any single Cys residue reduced surface
      expression levels by 40-70%. However, mutation of Cys101 or Cys178, predicted to 
      link ECL1 and ECL2 of the receptor, abolished recognition of CCR5 by a panel of
      conformation sensitive anti-CCR5 antibodies. The effects of the mutations on
      receptor expression and conformation were partially temperature-sensitive, with
      partial restoration of receptor expression and conformation achieved by
      incubating cells at 32 degrees C. All cysteine mutants were unable to bind
      detectable levels of MIP-1beta, and did not respond functionally to CCR5
      agonists. Surprisingly, all cysteine mutants did support infection by R5 strains 
      of HIV, though at reduced levels. These results indicate that both disulfide
      bonds of CCR5 are necessary for maintaining the structural integrity of the
      receptor necessary for ligand binding and signaling. Env binding and the
      mechanisms of HIV entry appear much less sensitive to alterations of CCR5
      conformation.
FAU - Blanpain, C
AU  - Blanpain C
AD  - Institut de Recherche Interdisciplinaire, Universite Libre de Bruxelles, Campus
      Erasme, 808 route de Lennik, B-1070 Bruxelles, Belgium.
FAU - Lee, B
AU  - Lee B
FAU - Vakili, J
AU  - Vakili J
FAU - Doranz, B J
AU  - Doranz BJ
FAU - Govaerts, C
AU  - Govaerts C
FAU - Migeotte, I
AU  - Migeotte I
FAU - Sharron, M
AU  - Sharron M
FAU - Dupriez, V
AU  - Dupriez V
FAU - Vassart, G
AU  - Vassart G
FAU - Doms, R W
AU  - Doms RW
FAU - Parmentier, M
AU  - Parmentier M
LA  - eng
GR  - R01 AI40880/AI/NIAID NIH HHS/United States
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - J Biol Chem
JT  - The Journal of biological chemistry
JID - 2985121R
RN  - 0 (Chemokine CCL4)
RN  - 0 (Chemokines)
RN  - 0 (Disulfides)
RN  - 0 (Ligands)
RN  - 0 (Macrophage Inflammatory Proteins)
RN  - 0 (Receptors, CCR5)
RN  - K848JZ4886 (Cysteine)
SB  - IM
SB  - X
MH  - Amino Acid Substitution
MH  - Animals
MH  - CHO Cells
MH  - Cell Line
MH  - Chemokine CCL4
MH  - Chemokines/*metabolism
MH  - Cricetinae
MH  - Cysteine/*metabolism
MH  - Disulfides/metabolism
MH  - HIV-1/*metabolism
MH  - Humans
MH  - Ligands
MH  - Macrophage Inflammatory Proteins/metabolism
MH  - Models, Molecular
MH  - Mutagenesis, Site-Directed
MH  - Protein Conformation
MH  - Receptors, CCR5/genetics/*metabolism
EDAT- 1999/06/26 00:00
MHDA- 1999/06/26 00:01
CRDT- 1999/06/26 00:00
PHST- 1999/06/26 00:00 [pubmed]
PHST- 1999/06/26 00:01 [medline]
PHST- 1999/06/26 00:00 [entrez]
AID - 10.1074/jbc.274.27.18902 [doi]
PST - ppublish
SO  - J Biol Chem. 1999 Jul 2;274(27):18902-8. doi: 10.1074/jbc.274.27.18902.