Abstract
Basal adenylyl cyclase activity in lung membranes isolated from hypersensitive guinea pigs was increased and more sensitive to stimulation by isoprenaline, GTP and GppNHp when compared to adenylyl cyclase in lung membranes isolated from normal healthy guinea pigs. Maximal forskolin-stimulated adenylyl cyclase activity was unaltered. There was no change in the immunological quantitative amounts of either alpha subunits of the G proteins G(iII) and G(s) (G(o), G(iI) and G(iIII) were not present). Maximal pertussis-toxin- and cholera-toxin-catalyzed ADP-ribosylation of G(ialpha) and G(salpha) respectively were not significantly altered. The addition of purified protein kinase C to isolated lung membranes resulted in the phosphorylation of the alpha subunit of G(s) (stoichiometry was 0.53 mol of P-32 incorporated/mol of G(salpha)). Addition of protein kinase C to lung membranes isolated from hypersensitive guinea pigs was equally effective at catalysing the phosphorylation of the alpha subunit of G(s). GppNHp-stimulated and basal adenylyl cyclase activity was also enhanced in isolated tracheal smooth-muscle membranes from hypersensitive guinea pigs. These results suggest that hypersensitive reactions are associated with the improved coupling of the stimulatory G protein (G(s)) with adenylyl cyclase.
| Original language | English |
|---|---|
| Pages (from-to) | 313-320 |
| Number of pages | 8 |
| Journal | BBA - Biochimica et Biophysica Acta |
| Volume | 1176 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - 16 Apr 1993 |
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Keywords
- adenylyl cyclase
- cholera-toxin
- protein kinase C; (Lung)
- hypersensitivity
- binding protein
- phosphorylation
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Adenylyl cyclase in lung from hypersensitive guinea pig displays increased responsiveness to guanine nucleotides and isoprenaline: The role of the G proteins Gs and Gi. / GRADY, M ; STEVENS, P A ; PYNE, S ; PYNE, N .
In: BBA - Biochimica et Biophysica Acta, Vol. 1176, No. 3, 16.04.1993, p. 313-320.Research output: Contribution to journal › Article
TY - JOUR
T1 - Adenylyl cyclase in lung from hypersensitive guinea pig displays increased responsiveness to guanine nucleotides and isoprenaline: The role of the G proteins Gs and Gi
AU - GRADY, M
AU - STEVENS, P A
AU - PYNE, S
AU - PYNE, N
PY - 1993/4/16
Y1 - 1993/4/16
N2 - Basal adenylyl cyclase activity in lung membranes isolated from hypersensitive guinea pigs was increased and more sensitive to stimulation by isoprenaline, GTP and GppNHp when compared to adenylyl cyclase in lung membranes isolated from normal healthy guinea pigs. Maximal forskolin-stimulated adenylyl cyclase activity was unaltered. There was no change in the immunological quantitative amounts of either alpha subunits of the G proteins G(iII) and G(s) (G(o), G(iI) and G(iIII) were not present). Maximal pertussis-toxin- and cholera-toxin-catalyzed ADP-ribosylation of G(ialpha) and G(salpha) respectively were not significantly altered. The addition of purified protein kinase C to isolated lung membranes resulted in the phosphorylation of the alpha subunit of G(s) (stoichiometry was 0.53 mol of P-32 incorporated/mol of G(salpha)). Addition of protein kinase C to lung membranes isolated from hypersensitive guinea pigs was equally effective at catalysing the phosphorylation of the alpha subunit of G(s). GppNHp-stimulated and basal adenylyl cyclase activity was also enhanced in isolated tracheal smooth-muscle membranes from hypersensitive guinea pigs. These results suggest that hypersensitive reactions are associated with the improved coupling of the stimulatory G protein (G(s)) with adenylyl cyclase.
AB - Basal adenylyl cyclase activity in lung membranes isolated from hypersensitive guinea pigs was increased and more sensitive to stimulation by isoprenaline, GTP and GppNHp when compared to adenylyl cyclase in lung membranes isolated from normal healthy guinea pigs. Maximal forskolin-stimulated adenylyl cyclase activity was unaltered. There was no change in the immunological quantitative amounts of either alpha subunits of the G proteins G(iII) and G(s) (G(o), G(iI) and G(iIII) were not present). Maximal pertussis-toxin- and cholera-toxin-catalyzed ADP-ribosylation of G(ialpha) and G(salpha) respectively were not significantly altered. The addition of purified protein kinase C to isolated lung membranes resulted in the phosphorylation of the alpha subunit of G(s) (stoichiometry was 0.53 mol of P-32 incorporated/mol of G(salpha)). Addition of protein kinase C to lung membranes isolated from hypersensitive guinea pigs was equally effective at catalysing the phosphorylation of the alpha subunit of G(s). GppNHp-stimulated and basal adenylyl cyclase activity was also enhanced in isolated tracheal smooth-muscle membranes from hypersensitive guinea pigs. These results suggest that hypersensitive reactions are associated with the improved coupling of the stimulatory G protein (G(s)) with adenylyl cyclase.
KW - adenylyl cyclase
KW - cholera-toxin
KW - protein kinase C; (Lung)
KW - hypersensitivity
KW - binding protein
KW - phosphorylation
U2 - 10.1016/0167-4889(93)90060-3
DO - 10.1016/0167-4889(93)90060-3
M3 - Article
VL - 1176
SP - 313
EP - 320
JO - BBA - Biochimica et Biophysica Acta
JF - BBA - Biochimica et Biophysica Acta
SN - 0006-3002
IS - 3
ER -