GoProtein Does Not Regulate ATP-Stimulated [Ca2+]iElevation or Noradrenaline Release in PC12 Cells

Oda, Haruko; Murayama, Toshihiko; Nomura, Yasuyuki

doi:10.1006/abbi.1996.0309

Cited by 8 publications

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In PC12 cells, trimeric G proteins exerted an influence on the regulation of secretory vesicle formation and mastoparan inhibited the formation (Leyte et al, 1992). CTX treatment for 24 h inhibited not only mastoparan-but also high K'and purinergic receptorstimulated I3H1NA release (data not shown, but see Oda et al, 1996). Thus, CTX-sensitive substrates may be generally involved in secretion system.…”

Section: Fig 3 Adp-ribosylation Of Gs In the Membrane Fraction Of Pmentioning

confidence: 88%

“…L3H1NA release from PC12 cells PC12 (D-type) cells were grown under 10% CO, at 37"C, in collagen-coated dishes in Dulbecco's modified essential medium supplemented with 5% heat-inactivated fetal bovine serum and horse serum as described previously (Kurozumi et al, 1990;Oda et al, 1995Oda et al, , 1996. In some experiments, 1 pg/ml of PTX (a gift from Kaken-Seiyaku Corp., Japan) or CTX (List Biological Lab.)…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Pertussis toxin-insensitive effects of mastoparan, a wasp venom peptide, in PC 12 cells

1996

Self Cite

View full text Add to dashboard Cite

Recent studies have shown that mastoparan, an amphiphilic peptide derived from wasp venom, modifies the secretion of neurotransmitters and hormones from a variety of cell types. Mastoparan interacts with heterotrimeric guanine nucleotide-binding proteins (G proteins) such as Gi and G(o), which are ADP-ribosylated by pertussis toxin (PTX) and thereby uncoupled from receptors. Previously, some of the effects of mastoparan including secretion were reported to be modified selectively by PTX but not by cholera toxin (CTX). In the present study, we examined the influence of bacterial toxins on the effects of mastoparan in PC12 cells. Mastoparan stimulated [3H]noradrenaline (NA) release from prelabeled PC12 cells in the absence of CaCl2, although high K+ or ATP-stimulated the release in a Ca(2+)-dependent manner. Pretreatment with CTX, not PTX, for 24 h inhibited mastoparan-stimulated [3H]NA release. Mastoparan inhibited forskolin-stimulated cyclic AMP accumulation in a dose-dependent manner, although mastoparan had no effect by itself. Pretreatment with PTX completely abolished the inhibitory effect of carbachol via Gi on cyclic AMP accumulation and partially reduced the effect of mastoparan. However, the inhibitory effect of 20 microM mastoparan was not modified by pretreatment with PTX. Thus, we investigated the effect of mastoparan on CTX-catalyzed [32P]ADP-ribosylation of proteins in PC12 cells. A subunit of CTX (CTX-A) catalyzed [32P]ADP-ribosylation of many proteins in the cytosolic fraction of PC12 cells. One of these was a 20 kDa protein, named ADP-ribosylating factor (ARF). The addition of mastoparan to assay mixtures inhibited ADP-ribosylation of many proteins including ARF and CTX-A in the presence of the cytosolic fraction. In the absence of the cytosolic fraction, however, mastoparan slightly enhanced ADP-ribosylation of bovine serum albumin and auto-ADP-ribosylation by CTX-A. Mastoparan did not inhibit ADP-ribosylation of the alpha subunit of Gs in the membrane fraction. These findings suggest that 1) mastoparan interacts with PTX-insensitive and CTX-sensitive factor(s) to stimulate NA release, and 2) mastoparan interacts with ARF inhibiting its activity to enhance the ADP-ribosylation reaction by CTX. ARF may be an exocytosis-linked G protein.

show abstract

Section: Fig 3 Adp-ribosylation Of Gs In the Membrane Fraction Of Pmentioning

confidence: 88%

Section: Methodsmentioning

confidence: 99%