Adenylate cyclase systems consist of inhibitory and stimulatory receptors linked to a catalytic unit through inhibitory and stimulatory proteins, Gi and Gs, respectively. Similarly, the retinal photon receptor rhodopsin is linked with a phosphodiesterase through transducin (T), which is similar to Gs and Gi. Each has a guanyl nucleotide-binding Alpha subunit (45 kDa Gs, 41 kDa Gi, and 39 kDa T) and Beta, Gamma subunit (35 and l0 kDa). Gs and Gi can be activated by NaF with AlCl3 and by decavadanate, as well as by agonists acting through specific receptors. The effects of NaF with AlCl3 and decavanadate on transducin were investigated in a reconstituted system consisting of the purified subunits of transducin (TAlpha, TBeta Gamma) and rhodopsin in prhosphatidylcholine vesicles. NaF noncompetitively inhibited the GTPase activity of TAlpha in a concentration- and time-dependent manner. Inhibition by NaF was enhanced synergistically by AlCl3 which alone only slighly inhibited GTPase activity. None of the other anions tested reproduced the effect of fluoride. Fluoride inhibited [3H]GppNHp binding to TAlpha and release of bound GDP. Vanadate (decameric) inhibited [3H]GTP binding to TAlpha and GTP hydrolysis in a concentration-dependent manner with maximal inhibition of approximately 90% at 3-5 mM. Vanadate also inhibited release of bound GDP. The ADP-ribosylation of TAlpha by pertussis toxin and binding of TAlpha to rhodopsin, both of which are enhanced in the presence of TBetaGamma, were inhibited by NaF with AlCl3 and by vanadate. These findings are consistent with the conclusion that NaF plus AlCl3 or vanadate can cause the dissociation of TAlpha from TBetaGamma, resulting in the inhibition of GDP-GTP exchange and thereby GTP hydrolysis. Adenylate cyclase activation and inhibition presumably result from similar effects of NaF plus AlCl3 and vanadate on Gs and Gi.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Intramural Research (Z01)
Project #
1Z01HL000627-07
Application #
4694493
Study Section
Project Start
Project End
Budget Start
Budget End
Support Year
7
Fiscal Year
1985
Total Cost
Indirect Cost
Name
U.S. National Heart Lung and Blood Inst
Department
Type
DUNS #
City
State
Country
United States
Zip Code
Puxeddu, Ermanno; Uhart, Marina; Li, Chun-Chun et al. (2009) Interaction of phosphodiesterase 3A with brefeldin A-inhibited guanine nucleotide-exchange proteins BIG1 and BIG2 and effect on ARF1 activity. Proc Natl Acad Sci U S A 106:6158-63
Citterio, Carmen; Vichi, Alessandro; Pacheco-Rodriguez, Gustavo et al. (2008) Unfolded protein response and cell death after depletion of brefeldin A-inhibited guanine nucleotide-exchange protein GBF1. Proc Natl Acad Sci U S A 105:2877-82
Shen, Xiaoyan; Hong, Myoung-Soon; Moss, Joel et al. (2007) BIG1, a brefeldin A-inhibited guanine nucleotide-exchange protein, is required for correct glycosylation and function of integrin beta1. Proc Natl Acad Sci U S A 104:1230-5
Islam, Aminul; Shen, Xiaoyan; Hiroi, Toyoko et al. (2007) The brefeldin A-inhibited guanine nucleotide-exchange protein, BIG2, regulates the constitutive release of TNFR1 exosome-like vesicles. J Biol Chem 282:9591-9
Li, Chun-Chun; Chiang, Tsai-Chen; Wu, Tsung-Sheng et al. (2007) ARL4D recruits cytohesin-2/ARNO to modulate actin remodeling. Mol Biol Cell 18:4420-37
Kuroda, Fuminobu; Moss, Joel; Vaughan, Martha (2007) Regulation of brefeldin A-inhibited guanine nucleotide-exchange protein 1 (BIG1) and BIG2 activity via PKA and protein phosphatase 1gamma. Proc Natl Acad Sci U S A 104:3201-6
Citterio, Carmen; Jones, Heather D; Pacheco-Rodriguez, Gustavo et al. (2006) Effect of protein kinase A on accumulation of brefeldin A-inhibited guanine nucleotide-exchange protein 1 (BIG1) in HepG2 cell nuclei. Proc Natl Acad Sci U S A 103:2683-8
Shen, Xiaoyan; Xu, Kai-Feng; Fan, Qingyuan et al. (2006) Association of brefeldin A-inhibited guanine nucleotide-exchange protein 2 (BIG2) with recycling endosomes during transferrin uptake. Proc Natl Acad Sci U S A 103:2635-40
Hiroi, Toyoko; Someya, Akimasa; Thompson, Walter et al. (2006) GEP100/BRAG2: activator of ADP-ribosylation factor 6 for regulation of cell adhesion and actin cytoskeleton via E-cadherin and alpha-catenin. Proc Natl Acad Sci U S A 103:10672-7
Xu, Kai-Feng; Shen, Xiaoyan; Li, Hewang et al. (2005) Interaction of BIG2, a brefeldin A-inhibited guanine nucleotide-exchange protein, with exocyst protein Exo70. Proc Natl Acad Sci U S A 102:2784-9

Showing the most recent 10 out of 33 publications