Adenylyl cyclases play a pivotal role in signal transduction by carrying out the regulated synthesis of cyclic AMP. The nine cloned mammalian adenylyl cyclases all share two conserved regions of sequence, C1 and C2, which are homologous to each other and are together responsible for catalytic activity. Using limited proteolysis and mass spectrometry, we have mapped the boundaries of a minimal stable and active C2 catalytic domain to resiudes 871-1090 of type II adenylyl cyclase. We determined the crystal structure of the C2 catalytic region at an effective resolution of 2.6 Angstroms. The structure has an alpha and beta fold in a wreath- like dimer, which has a central cleft. Two forskolin molecules bind in the hydrophobic pockets at the ends of the cleft. The central part of the cleft is lined with charged residues implicated in ATP binding. Forskolin activates adenylyl cyclase by promoting the assembly of the active dimer and by direct interaction within the catalytic cleft. The interaction between the alpha subunit of G protein s and the cytoplasmic domains of adenylyl cyclase is a key step in the stimulation of cAMP synthesis by hormones. Mutational analysis reveals three discrete regions in the primary sequence of adenylyl cyclase the affect the EC-50 values for Gsa activation, and thus are the affinity determinants of Gsa. The structure shows that these three regions are close together and form a negatively charged and hydrophobic groove the width of an alpha helix which can accommodate the positively charged adenylyl cyclase binding region of Gsa. These mutations are distal to the catalytic site hence modulate activity by controlling the orientation of two domains in the dimer.
| Yadav, Umesh C S; Srivastava, Satish K; Ramana, Kota V (2012) Prevention of VEGF-induced growth and tube formation in human retinal endothelial cells by aldose reductase inhibition. J Diabetes Complications 26:369-77 |
| Kalariya, Nilesh M; Shoeb, Mohammad; Ansari, Naseem H et al. (2012) Antidiabetic drug metformin suppresses endotoxin-induced uveitis in rats. Invest Ophthalmol Vis Sci 53:3431-40 |
| Pandey, Saumya; Srivastava, Satish K; Ramana, Kota V (2012) A potential therapeutic role for aldose reductase inhibitors in the treatment of endotoxin-related inflammatory diseases. Expert Opin Investig Drugs 21:329-39 |
| Srivastava, Satish K; Yadav, Umesh C S; Reddy, Aramati B M et al. (2011) Aldose reductase inhibition suppresses oxidative stress-induced inflammatory disorders. Chem Biol Interact 191:330-8 |
| Reddy, Aramati B M; Tammali, Ravinder; Mishra, Rakesh et al. (2011) Aldose reductase deficiency protects sugar-induced lens opacification in rats. Chem Biol Interact 191:346-50 |
| Yadav, Umesh C S; Shoeb, Mohammad; Srivastava, Satish K et al. (2011) Amelioration of experimental autoimmune uveoretinitis by aldose reductase inhibition in Lewis rats. Invest Ophthalmol Vis Sci 52:8033-41 |
| Tammali, Ravinder; Srivastava, Satish K; Ramana, Kota V (2011) Targeting aldose reductase for the treatment of cancer. Curr Cancer Drug Targets 11:560-71 |
| Yadav, Umesh C S; Shoeb, Mohammed; Srivastava, Satish K et al. (2011) Aldose reductase deficiency protects from autoimmune- and endotoxin-induced uveitis in mice. Invest Ophthalmol Vis Sci 52:8076-85 |
| Tammali, Ravinder; Reddy, Aramati B M; Srivastava, Satish K et al. (2011) Inhibition of aldose reductase prevents angiogenesis in vitro and in vivo. Angiogenesis 14:209-21 |
| Shoeb, Mohammad; Yadav, Umesh C S; Srivastava, Satish K et al. (2011) Inhibition of aldose reductase prevents endotoxin-induced inflammation by regulating the arachidonic acid pathway in murine macrophages. Free Radic Biol Med 51:1686-96 |
Showing the most recent 10 out of 67 publications
