TY - JOUR
T1 - The hepatic Ah receptor for 2,3,7,8-Tetrachlorodibenzo-p-dioxin
T2 - Species differences in subunit dissociation
AU - Denison, Michael S.
AU - Vella, Lynn M.
PY - 1990
Y1 - 1990
N2 - 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD, dioxin) produces many of its biological effects by binding to a soluble, intracellar protein (the Ah receptor (AhR)). The hepatic AhR, from a variety of species, is present in low salt cytosol as a form which sediments at 8-10 S. High salt (0.4 m KCL) dissociates the rat, guinea pig, and rabbit cytosolic TCDD:AhR complex to a form which sediments at 5-6 S. In contrast, high salt conditions failed to dissociate the 8-10 S TCDD:AhR complex present in any of the mouse strains studied. Incubation of cytosol with heparin resulted in a shift of the [3H]TCDD:AhR complex to a smaller sedimenting form in all species. Mouse TCDD:AhR complex sedimented at 8-10 S when cytosol was simultaneously incubated with high salt and heparin, indicating that the interaction of heparin with the AhR was electrostatic in nature. Incubation of heparin-dissociated mouse TCDD: AhR complex (5-6 S) with high salt resulted in reassociation of AhR to a form which sediments at 8-10 S. Our data suggests that the resistance of mouse AhR to salt-mediated dissociation may be due to a property of the receptor protein itself and also indicates that mouse hepatic cytosolic AhR is distinctly different from that present in all other species examined to date.
AB - 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD, dioxin) produces many of its biological effects by binding to a soluble, intracellar protein (the Ah receptor (AhR)). The hepatic AhR, from a variety of species, is present in low salt cytosol as a form which sediments at 8-10 S. High salt (0.4 m KCL) dissociates the rat, guinea pig, and rabbit cytosolic TCDD:AhR complex to a form which sediments at 5-6 S. In contrast, high salt conditions failed to dissociate the 8-10 S TCDD:AhR complex present in any of the mouse strains studied. Incubation of cytosol with heparin resulted in a shift of the [3H]TCDD:AhR complex to a smaller sedimenting form in all species. Mouse TCDD:AhR complex sedimented at 8-10 S when cytosol was simultaneously incubated with high salt and heparin, indicating that the interaction of heparin with the AhR was electrostatic in nature. Incubation of heparin-dissociated mouse TCDD: AhR complex (5-6 S) with high salt resulted in reassociation of AhR to a form which sediments at 8-10 S. Our data suggests that the resistance of mouse AhR to salt-mediated dissociation may be due to a property of the receptor protein itself and also indicates that mouse hepatic cytosolic AhR is distinctly different from that present in all other species examined to date.
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U2 - 10.1016/0003-9861(90)90594-O
DO - 10.1016/0003-9861(90)90594-O
M3 - Article
C2 - 2155580
AN - SCOPUS:0025220130
VL - 277
SP - 382
EP - 388
JO - Archives of Biochemistry and Biophysics
JF - Archives of Biochemistry and Biophysics
SN - 0003-9861
IS - 2
ER -