Effects of guanine nucleotides on cholera toxin catalyzed ADP-ribosylation in rat adipocyte plasma membranes

Biochemistry ◽  
1983 ◽  
Vol 22 (26) ◽  
pp. 6291-6296 ◽  
Author(s):  
C. Bruce Graves ◽  
Nancy B. Klaven ◽  
Jay M. McDonald
Keyword(s):  
Cholera Toxin ◽  
Plasma Membranes ◽  
Guanine Nucleotides ◽  
Adp Ribosylation ◽  
Adipocyte Plasma Membranes

Alterations of adenylyl cyclase-linked G proteins in rat liver during aging

1996 ◽  
Vol 270 (1) ◽  
pp. E126-E132 ◽  
Author(s):  
A. T. Eakes ◽  
T. K. Hymer ◽  
M. J. Rosenthal ◽  
J. Moss ◽  
M. S. Katz
Keyword(s):  
Adenylyl Cyclase ◽  
Cholera Toxin ◽  
G Proteins ◽  
Rat Liver ◽  
Plasma Membranes ◽  
Adrenergic Stimulation ◽  
Beta Adrenergic ◽  
Adp Ribosylation ◽  
Old Rats ◽  
Gs Alpha

beta-Adrenergic stimulation of adenylyl cyclase in rat liver increases during aging. We examined whether this increase is related to alterations in the stimulatory and inhibitory G proteins (Gs and Gi) linked to adenylyl cyclase. Levels of immunoreactive alpha- and beta-subunits of Ga and Gi in liver plasma membranes from 6-, 12-, 18-, and 24-mo-old rats were unchanged with age, as was pertussis toxin-catalyzed [32P]ADP ribosylation of Gi alpha. Cholera toxin-catalyzed [32P]ADP ribosylation of Ga alpha and Gs bioactivity, assessed as reconstitution of adenylyl cyclase activity in S49 cyc- cell membranes, increased two- to threefold between 6 and 12-18 mo, and declined by 24 mo. Recombinant ADP ribosylation factor (ARF) enhanced cholera toxin labeling of Gs alpha at all ages, yet abolished the increase in toxin labeling at 12-18 mo. Auto-ADP ribosylation of the cholera toxin A1 peptide also increased transiently with age. Alteration of Gs alpha, as reflected by increased cholera toxin labeling and Gs bioactivity, may be involved in the regulation of beta-adrenergic-responsive adenylyl cyclase in rat liver during aging. Moreover, changes in endogenous ARF levels could contribute to age differences in cholera toxin labeling of Gs alpha.

scholarly journals Requirement for guanosine triphosphate for cholera-toxin-catalysed incorporation of adenosine diphosphate ribose into rat liver plasma membranes and for activation of adenylate cyclase

1980 ◽  
Vol 186 (3) ◽  
pp. 749-754 ◽  
Author(s):  
C A Doberska ◽  
A J S MacPherson ◽  
B R Martin
Keyword(s):  
Plasma Membrane ◽  
Adenylate Cyclase ◽  
Cholera Toxin ◽  
Rat Liver ◽  
Plasma Membranes ◽  
Adenosine Diphosphate ◽  
Activation Process ◽  
Liver Plasma Membrane ◽  
Adp Ribosylation ◽  
A Subunit

1. Cholera toxin was shown to require the presence of GTP to activate rat liver plasma-membrane adenylate cyclase. ATP did not affect the activation process. 2. Cholera toxin catalysed the incorporation of 32P from NAD labelled in the alpha-phosphate group of the ADP moiety into a rat liver plasma-membrane protein with a subunit mol.wt. of 42 500. This is taken to demonstrate ADP-ribosylation. The ADP-ribosylation of this protein also required GTP and was unaffected by ATP. 3. Nicotinamide inhibited both the activation of adenylate cyclase by cholera toxin and the ADP-ribosylation of the protein of 42 500 subunit mol wt. Neither the activation nor the ADP-ribosylation could be reversed by treatment with nicotinamide in the presence of cholera toxin.

scholarly journals Differential cholera-toxin- and pertussis-toxin-catalysed ADP-ribosylation of G-proteins coupled to formyl-peptide and leukotriene B4 receptors

1993 ◽  
Vol 289 (2) ◽  
pp. 469-473 ◽  
Author(s):  
T M Schepers ◽  
K R McLeish
Keyword(s):  
Cholera Toxin ◽  
G Proteins ◽  
Pertussis Toxin ◽  
Leukotriene B4 ◽  
Guanine Nucleotides ◽  
Dependent Manner ◽  
Functional Responses ◽  
Concentration Dependent Manner ◽  
Adp Ribosylation ◽  
Formyl Peptide

N-Formylmethionyl-leucyl-phenylalanine (fMet-Leu-Phe) and leukotriene B4 (LTB4) induce disparate second-messenger generation and functional responses in neutrophils and HL-60 granulocytes. Receptors for these chemoattractants couple to a common pool of G-proteins which are substrates for both pertussis-toxin- and cholera-toxin-catalysed ADP-ribosylation. The hypothesis that formyl-peptide and LTB4 receptors induce different receptor-specific conformations of activated G-proteins was tested. The ability of pertussis toxin and cholera toxin to ADP-ribosylate G(i) proteins coupled to formyl-peptide or LTB4 receptors in membranes isolated from HL-60 granulocytes was used to assess the conformational state of the alpha subunits. Cholera-toxin-catalysed ADP-ribosylation of alpha 40 (40 kDa alpha subunit) was inhibited by guanosine 5′-[beta gamma-imido]triphosphate and GDP in a concentration-dependent manner. Addition of fMet-Leu-Phe, but not LTB4, re-established cholera-toxin labelling of alpha 40 in the presence of either guanine nucleotide. In the absence of guanine nucleotides, fMet-Leu-Phe and C5a enhanced cholera-toxin-catalysed labelling of alpha 40, whereas LTB4 and platelet-activating factor had no effect. Preincubation with fMet-Leu-Phe, but not LTB4, inhibited pertussis-toxin labelling of alpha 40 in the presence of guanosine 5′-[gamma-thio]triphosphate and in the absence of guanine nucleotides. Preincubation with fMet-Leu-Phe or LTB4 enhanced pertussis-toxin labelling of alpha 40 in the presence of GDP. These data suggest that activated G(i) proteins coupled to formyl-peptide and LTB4 receptors exist in different conformations determined by the receptor with which they interact.

Mechanism of Activation of Cholera Toxin by ADP-Ribosylation Factor (ARF): Both Low- and High-Affinity Interactions of ARF with Guanine Nucleotides Promote Toxin Activation

Biochemistry ◽  
1990 ◽  
Vol 29 (4) ◽  
pp. 855-861 ◽  
Author(s):  
David Bobak ◽  
Matthew Bliziotes ◽  
Masatoshi Noda ◽  
Su-Chen Tsai ◽  
Ronald Adamik ◽  
...  
Keyword(s):  
Cholera Toxin ◽  
Guanine Nucleotides ◽  
Adp Ribosylation ◽  
High Affinity ◽  
Adp Ribosylation Factor
Sign in / Sign up

Export Citation Format

Share Document