Broderick, K. E., MacPherson, M. R., Regulski, M., Tully, T., Dow, J. A. T., Davies, S. A. (November 2003) Interactions between epithelial nitric oxide signaling and phosphodiesterase activity in Drosophila. American Journal of Physiology-Cell Physiology, 285 (5). C1207-C1218. ISSN 0363-6143
Abstract
Signaling by nitric oxide (NO) and guanosine 3',5'-cyclic monophosphate (cGMP) modulates fluid transport in Drosophila melanogaster. Expression of an inducible transgene encoding Drosophila NO synthase (dNOS) increases both NOS activity in Malpighian (renal) tubules and DNOS protein in both type I (principal) and type II (stellate) cells. However, cGMP content is increased only in principal cells. DNOS overexpression results in elevated basal rates of fluid transport in the presence of the phosphodiesterase (PDE) inhibitor, Zaprinast. Direct assay of tubule cGMP-hydrolyzing phosphodiesterase (cG-PDE) activity in wild-type and dNOS transgenic lines shows that cG-PDE activity is Zaprinast sensitive and is elevated upon dNOS induction. Zaprinast treatment increases cGMP content in tubules, particularly at the apical regions of principal cells, suggesting localization of Zaprinast-sensitive cG-PDE to these areas. Potential cross talk between activated NO/cGMP and calcium signaling was assessed in vivo with a targeted aequorin transgene. Activated DNOS signaling alone does not modify either neuropeptide (CAP(2b))- or cGMP-induced increases in cytosolic calcium levels. However, in the presence of Zaprinast, both CAP(2b)- and cGMP-stimulated calcium levels are potentiated upon DNOS overexpression. Use of the calcium channel blocker, verapamil, abolishes the Zaprinast-induced transport phenotype in dNOS-overexpressing tubules. Molecular genetic intervention in the NO/cGMP signaling pathway has uncovered a pivotal role for cell-specific cG-PDE in regulating the poise of the fluid transporting Malpighian tubule via direct effects on intracellular cGMP concentration and localization and via interactions with calcium signaling mechanisms.
| Item Type: | Paper |
|---|---|
| Uncontrolled Keywords: | Malpighian tubule cGMP calcium aequorin CNG channel DEPENDENT PROTEIN-KINASE GUANYLATE-CYCLASE ION-CHANNEL V-ATPASE MELANOGASTER KIDNEY CELLS CGMP TRANSPORT FAMILY |
| Subjects: | organism description > animal > insect > Drosophila bioinformatics > genomics and proteomics > small molecules > nitric oxide organs, tissues, organelles, cell types and functions > tissues types and functions > signal transduction bioinformatics > genomics and proteomics > small molecules |
| CSHL Authors: | |
| Communities: | CSHL labs > Tully lab |
| Depositing User: | Matt Covey |
| Date: | November 2003 |
| Date Deposited: | 11 Jun 2013 16:15 |
| Last Modified: | 11 Jun 2013 16:15 |
| Related URLs: | |
| URI: | https://repository.cshl.edu/id/eprint/27954 |
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