Interaction of C1 with HIV-1.
In contrast to animal retroviruses such as murine leukemia virus, HIV-1 is not lysed by human complement. Nevertheless, HIV-1 activates complement via the classical pathway independently of antibody. Evidence is provided for activation of the reconstituted C1 complex by the virus, resulting from direct interaction between C1q and the external part of the viral transmembrane envelope protein (sgp41). Using C1q fragments and synthetic peptides covering the putative interaction regions in C1q and sgp41, we obtain evidence that the C1q/HIV-1 interaction involves: A site on C1q that appears to be located in the intermediary region between the collagen-like and the globular regions of C1q, and which may be conformational, involving two or more C1q chains. A site on gp41 located between residues 601 and 613 (gp160 nomenclature), i.e. within the immunodominant domain of HIV-1. This site shares homology with the corresponding region of HIV-2.
Thielens
N M
NM
Institut de Biologie Structurale, Laboratire d'Enzymologie Moleculaire, Grenoble, France.
Bally
I M
IM
Ebenbichler
C F
CF
Dierich
M P
MP
Arlaud
G J
GJ
D000595:Amino Acid Sequence; D001665:Binding Sites; D003172:Complement C1 / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D003171:Complement Pathway, Classical; D015700:HIV Envelope Protein gp41 / Q000187:drug effects / Q000378:metabolism*; D015497:HIV-1 / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis / Q000494:pharmacology; D011994:Recombinant Proteins / Q000378:metabolism
D003172:Complement C1; D015700:HIV Envelope Protein gp41; D010455:Peptides; D011994:Recombinant Proteins