Mutations in the immunoglobulin-like domain of gp190, the leukemia inhibitory factor (LIF) receptor, increase or decrease its affinity for LIF.
The leukemia inhibitory factor (LIF) receptor comprises the low affinity binding chain gp190 and the high affinity converter gp130. The ectodomain of gp190 is among the most complex in the hematopoietin receptor family, because it contains two typical cytokine receptor homology domains separated by an immunoglobulin-like (Ig-like) domain. Human and murine gp190 proteins share 76% homology, but murine gp190 binds human LIF with a much higher affinity, a property attributed to the Ig-like domain. Using alanine-scanning mutagenesis of the Ig-like domain, we mapped a LIF binding site at its carboxyl terminus, mainly involving residue Phe-328. Mutation of selected residues into their orthologs in the murine receptor (Q251E and N321D) significantly increased the affinity for human LIF. Interestingly, these residues, although localized at both the amino and carboxyl terminus, make a spatially unique LIF binding site in a structural model of the Ig-like module. These results demonstrate definitively the role of the Ig-like domain in LIF binding and the potential to modulate receptor affinity in this family with very limited amino acid changes.
Bitard
Juliette
J
CNRS UMR 5540, Université de Bordeaux 2, 146 rue Léo Saignat, 33076 Bordeaux, France.
Daburon
Sophie
S
Duplomb
Laurence
L
Blanchard
Frédéric
F
Vuisio
Patricia
P
Jacques
Yannick
Y
Godard
Anne
A
Heath
John K
JK
Moreau
Jean-François
JF
Taupin
Jean-Luc
JL
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D016466:CHO Cells; D019556:COS Cells; D002455:Cell Division; D006224:Cricetinae; D004268:DNA-Binding Proteins / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D006131:Growth Inhibitors / Q000378:metabolism*; D006801:Humans; D007136:Immunoglobulins / Q000737:chemistry*; D015850:Interleukin-6; D053605:Leukemia Inhibitory Factor; D053680:Leukemia Inhibitory Factor Receptor alpha Subunit; D008222:Lymphokines / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D053683:Oncostatin M; D010455:Peptides / Q000378:metabolism; D010766:Phosphorylation; D017354:Point Mutation; D018121:Receptors, Cytokine / Q000737:chemistry* / Q000378:metabolism; D053606:Receptors, OSM-LIF; D050796:STAT3 Transcription Factor; D013329:Structure-Activity Relationship; D020349:Surface Plasmon Resonance; D015534:Trans-Activators / Q000378:metabolism
D004268:DNA-Binding Proteins; D006131:Growth Inhibitors; D007136:Immunoglobulins; D015850:Interleukin-6; C507837:LIF protein, human; C507840:LIFR protein, human; D053605:Leukemia Inhibitory Factor; D053680:Leukemia Inhibitory Factor Receptor alpha Subunit; D008222:Lymphokines; C508351:OSM protein, human; D010455:Peptides; D018121:Receptors, Cytokine; D053606:Receptors, OSM-LIF; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; D015534:Trans-Activators; D053683:Oncostatin M