C. Hecker et al., SPECIFIC BINDING OF HIV-1 ENVELOPE PROTEIN GP120 TO THE STRUCTURAL MEMBRANE-PROTEINS EZRIN AND MOESIN, Virus research, 49(2), 1997, pp. 215-223
The observation that HIV in vitro can infect CD4-and Gal-C-negative br
ain cell lines has stimulated this study to identify alternative gp120
-binding proteins on brain cells. HIV-1 gp120 binding proteins of the
CD4-negative and Gal-C-negative, non-productively infectable human gli
oblastoma cell line D54 were purified by affinity chromatography over
a gp120-conjugated sepharose column and identified by peptide microseq
uencing. The binding capacity and specificity of this column was contr
olled using extracts of CD4-positive cells. Two of seven prominent pro
teins eluted from the gp120 affinity column specifically bound gp120 i
n Western blot overlay experiments and were identified by subsequent i
mmunoblotting and microsequencing as ezrin and moesin, members of the
ERM (ezrin, radixin, moesin) family of cellular structural membrane pr
oteins. Antibodies to ezrin and moesin specifically recognized the elu
ted gp120 binding proteins confirming their identification. Ezrin and
moesin are structural proteins binding to the cellular membrane and to
several cytoskeletal and transmembrane proteins. Our results suggest
that ezrin and moesin might play a role as gp160/gp120 binding protein
s during the uptake, the assembly or the budding of HIV. (C) 1997 Else
vier Science B.V.