|
|
|
|||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
First published online July 2, 2004
Journal of Experimental Biology 207, 2769-2776 (2004)
Published by The Company of Biologists 2004
doi: 10.1242/jeb.01086
The dg2 (for) gene confers a renal phenotype in Drosophila by modulation of cGMP-specific phosphodiesterase

1 Institute of Biomedical and Life Sciences, Division of Molecular Genetics,
University of Glasgow, Glasgow G11 6NU, UK
2 Institute of Biomedical and Life Sciences, Division of Biochemistry and
Molecular Biology, University of Glasgow, Glasgow G11 6NU, UK
Author for correspondence (e-mail:
s.a.davies{at}bio.gla.ac.uk)
Accepted 12 May 2004
Fluid transport in Drosophila melanogaster tubules is regulated by guanosine 3',5'-cyclic monophosphate (cGMP) signalling. Here we compare the functional effects on tubules of different alleles of the dg2 (foraging or for) gene encoding a cGMP-dependent protein kinase (cGK), and show that the fors allele confers an epithelial phenotype. This manifests itself as hypersensitivity of epithelial fluid transport to the nitridergic neuropeptide, capa-1, which acts through nitric oxide and cGMP. However, there was no significant difference in tubule cGK activity between fors and forR adults. Nonetheless, fors tubules contained higher levels of cGMP-specific phosphodiesterase (cG-PDE) activity compared to forR. This increase in cGMP-PDE activity sufficed to decrease cGMP content in fors tubules compared to forR. Challenge of tubules with capa-1 increases cGMP content in both fors and forR tubules, although the increase from resting cGMP levels is greater in fors tubules. Capa-1 stimulation of tubules reveals a potent inhibition of cG-PDE in both lines, although this is greater in fors; and is sufficient to explain the hypersensitive transport phenotype observed.
Thus, polymorphisms at the dg2 locus do indeed confer a cGMP-dependent transport phenotype, but this can best be ascribed to an indirect modulation of cG-PDE activity, and thence cGMP homeostasis, rather than a direct effect on cGK levels.
Key words: Malpighian tubule, cyclic nucleotide, capa-1, epithelial transport, Drosophila melanogaster, dg2 locus
Related articles in JEB:
This article has been cited by other articles:
![]() |
M. R. MacPherson, S. M. Lohmann, and S.-A. Davies Analysis of Drosophila cGMP-dependent Protein Kinases and Assessment of Their in Vivo Roles by Targeted Expression in a Renal Transporting Epithelium J. Biol. Chem., September 17, 2004; 279(38): 40026 - 40034. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Phillips SECRETION SIGNALLING J. Exp. Biol., July 15, 2004; 207(16): ii - ii. [Full Text] [PDF] |
||||