Identification of the F1-ATPase at the cell surface of colonic epithelial cells: role in mediating cell proliferation.
F1 domain of F(1)F(o)-ATPase was initially believed to be strictly expressed in the mitochondrial membrane. Interestingly, recent reports have shown that the F1 complex can serve as a cell surface receptor for apparently unrelated ligands. Here we show for the first time the presence of the F(1)-ATPase at the cell surface of normal or cancerous colonic epithelial cells. Using surface plasmon resonance technology and mass spectrometry, we identified a peptide hormone product of the gastrin gene (glycine-extended gastrin (G-gly)) as a new ligand for the F(1)-ATPase. By molecular modeling, we identified the motif in the peptide sequence (E(E/D)XY), that directly interacts with the F(1)-ATPase and the amino acids in the F(1)-ATPase that bind this motif. Replacement of the Glu-9 residue by an alanine in the E(E/D)XY motif resulted in a strong decrease of G-gly binding to the F(1)-ATPase and the loss of its biological activity. In addition we demonstrated that F(1)-ATPase mediates the growth effects of the peptide. Indeed, blocking F(1)-ATPase activity decreases G-gly-induced cell growth. The mechanism likely involves ADP production by the membrane F(1)-ATPase, which is induced by G-gly. These results suggest an important contribution of cell surface F(1)-ATPase in the pro-proliferative action of this gastrointestinal peptide.
INSERM UMR 1037, Cancer Research Centre of Toulouse, Université Paul Sabatier Toulouse III, 31052 Toulouse, France.
Aline
A
Kowalski-Chauvel
Souad
S
Najib
Irina G
IG
Tikhonova
Laurence
L
Huc
Fredéric
F
Lopez
Laurent O
LO
Martinez
Elizabeth
E
Cohen-Jonathan-Moyal
Audrey
A
Ferrand
Catherine
C
Seva
D000244:Adenosine Diphosphate / Q000737:chemistry; D000595:Amino Acid Sequence; D000818:Animals; D018938:Caco-2 Cells; D020134:Catalytic Domain; D002417:Cattle; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000201:enzymology*; D049109:Cell Proliferation; D003106:Colon / Q000201:enzymology*; D015179:Colorectal Neoplasms / Q000378:metabolism; D042783:Endothelial Cells / Q000166:cytology; D004847:Epithelial Cells / Q000378:metabolism*; D006801:Humans; D008928:Mitochondria / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry; D006180:Proton-Translocating ATPases / Q000737:chemistry*; D017386:Sequence Homology, Amino Acid; D020349:Surface Plasmon Resonance
D010455:Peptides; D000244:Adenosine Diphosphate; D006180:Proton-Translocating ATPases