TY - JOUR
T1 - Activation of Helicobacter pylori VacA toxin by alkaline or acid conditions increases its binding to a 250-kDa receptor protein-tyrosine phosphatase β
AU - Yahiro, Kinnosuke
AU - Niidome, Takuro
AU - Kimura, Miyuki
AU - Hatakeyama, Tomomitsu
AU - Aoyagi, Haruhiko
AU - Kurazono, Hisao
AU - Imagawa, Ken Ichi
AU - Wada, Akihiro
AU - Moss, Joel
AU - Hirayama, Toshiya
PY - 1999/12/17
Y1 - 1999/12/17
N2 - Helicobacter pylori, a Gram-negative gastric bacterium, secretes VacA, a cytotoxin that causes vacuolar degeneration of susceptible cells. Velocity sedimentation analysis showed that treatment of VacA at alkaline pH led to disassembly of VacA oligomers, an observation reported previously for acid- treated VacA. Exposure of VacA to acid or alkali increased its binding to AZ- 521 cells, as shown by indirect immunofluorescence and flow cytometry. Moreover, immunoprecipitates with polyclonal antibodies against VacA from AZ- 521 cells previously exposed to acid- or alkali-treated VacA had a 250-kDa glycoprotein containing galactose-β(1-3)-N-acetylgalactosamine and galactose-β(1-4)-N-acetylglucosamine. p250, purified by chromatography on peanut agglutinin affinity and Superose 6 columns, contained N-terminal and internal amino acid sequences of YRQQRKLVEEIGWSYT and LIIQDHILEATQDDY, respectively. These sequences are identical to those of a receptor protein- tyrosine phosphatase (RPTPβ/PTPζ); in agreement, p250 reacted with anti- human RPTPβ monoclonal antibody. Immunopreeipitation with antihuman RPTPβ antibody of solubilized membrane preparations previously incubated with VacA or heat-inactivated VacA demonstrated that RPTPβ bound native, but not denatured, VacA. Acidic and alkaline treatments were associated with activation of VacA and increased binding to the cell surface RPTPβ.
AB - Helicobacter pylori, a Gram-negative gastric bacterium, secretes VacA, a cytotoxin that causes vacuolar degeneration of susceptible cells. Velocity sedimentation analysis showed that treatment of VacA at alkaline pH led to disassembly of VacA oligomers, an observation reported previously for acid- treated VacA. Exposure of VacA to acid or alkali increased its binding to AZ- 521 cells, as shown by indirect immunofluorescence and flow cytometry. Moreover, immunoprecipitates with polyclonal antibodies against VacA from AZ- 521 cells previously exposed to acid- or alkali-treated VacA had a 250-kDa glycoprotein containing galactose-β(1-3)-N-acetylgalactosamine and galactose-β(1-4)-N-acetylglucosamine. p250, purified by chromatography on peanut agglutinin affinity and Superose 6 columns, contained N-terminal and internal amino acid sequences of YRQQRKLVEEIGWSYT and LIIQDHILEATQDDY, respectively. These sequences are identical to those of a receptor protein- tyrosine phosphatase (RPTPβ/PTPζ); in agreement, p250 reacted with anti- human RPTPβ monoclonal antibody. Immunopreeipitation with antihuman RPTPβ antibody of solubilized membrane preparations previously incubated with VacA or heat-inactivated VacA demonstrated that RPTPβ bound native, but not denatured, VacA. Acidic and alkaline treatments were associated with activation of VacA and increased binding to the cell surface RPTPβ.
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U2 - 10.1074/jbc.274.51.36693
DO - 10.1074/jbc.274.51.36693
M3 - Article
C2 - 10593974
AN - SCOPUS:0033579575
VL - 274
SP - 36693
EP - 36699
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 51
ER -