TY - JOUR
T1 - The association of endogenous Goα with the purified ω-conotoxin GVIA receptor
AU - McEnery, Maureen W.
AU - Snowman, Adele M.
AU - Snyder, Solomon H.
N1 - Copyright:
Copyright 2007 Elsevier B.V., All rights reserved.
PY - 1994/1/7
Y1 - 1994/1/7
N2 - Modulation of the neuronal ω-conotoxin GVIA-sensitive N-type voltage-dependent calcium channel (VDCC) by neurotransmitters and guanine nucleotides suggests a dynamic interaction between activated G-protein α subunits and the N-type VDCC. Our previous report on the purification of the N-type VDCC (McEnery, M. W., Snowman, A. M., Sharp, A. H., Adams, M. E., and Snyder, S. H. (1991) Proc. Natl. Acad. Sci. U. S. A. 88, 11095-11099), has led us to investigate a possible association of CTXR with an endogenous Gα subunit. The addition of the G-protein activator AlF4- modulated the 125I-CTX binding characteristics of the solubilized CTXR. Further immunological analyses employing Gα subunit-specific antibodies to monitor the cofractionation of Gα with 125I-CTX binding activity throughout the purification procedure indicate the selective recovery of Goα in the purified CTXR preparation, as neither Gsα, Giα, nor Gβγ could be detected. Furthermore, Goα associated with CTXR acted as a substrate for pertussis toxin-dependent ADP-ribosylation only upon the addition of exogenous Gβγ subunits. These results strongly indicate a high affinity complex between an activated Goα and CTXR maintained throughout biochemical purification of the 125I-CTX receptor.
AB - Modulation of the neuronal ω-conotoxin GVIA-sensitive N-type voltage-dependent calcium channel (VDCC) by neurotransmitters and guanine nucleotides suggests a dynamic interaction between activated G-protein α subunits and the N-type VDCC. Our previous report on the purification of the N-type VDCC (McEnery, M. W., Snowman, A. M., Sharp, A. H., Adams, M. E., and Snyder, S. H. (1991) Proc. Natl. Acad. Sci. U. S. A. 88, 11095-11099), has led us to investigate a possible association of CTXR with an endogenous Gα subunit. The addition of the G-protein activator AlF4- modulated the 125I-CTX binding characteristics of the solubilized CTXR. Further immunological analyses employing Gα subunit-specific antibodies to monitor the cofractionation of Gα with 125I-CTX binding activity throughout the purification procedure indicate the selective recovery of Goα in the purified CTXR preparation, as neither Gsα, Giα, nor Gβγ could be detected. Furthermore, Goα associated with CTXR acted as a substrate for pertussis toxin-dependent ADP-ribosylation only upon the addition of exogenous Gβγ subunits. These results strongly indicate a high affinity complex between an activated Goα and CTXR maintained throughout biochemical purification of the 125I-CTX receptor.
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M3 - Article
C2 - 8276842
AN - SCOPUS:0028167586
SN - 0021-9258
VL - 269
SP - 5
EP - 8
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 1
ER -