TY - JOUR
T1 - Neuropeptide stimulation of the nitric oxide signaling pathway in Drosophila melanogaster Malpighian tubules
AU - Davies, Shireen A.
AU - Stewart, Eric J.
AU - Huesmann, Graham R.
AU - Skaer, Nicholas J.V.
AU - Maddrell, Simon H.P.
AU - Tublitz, Nathan J.
AU - Dow, Julian A.T.
PY - 1997
Y1 - 1997
N2 - Activation of the nitric oxide (NO) and guanosine 3',5'-cyclic monophosphate (cGMP) signaling pathway stimulates fluid secretion by the Drosophila melanogaster Malpighian tubule. The neuropeptide cardioacceleratory peptide 2b (CAP(2b)) has been previously shown to stimulate fluid secretion in this epithelium by elevating intracellular cGMP levels. Therefore, it was of interest to investigate if CAP(2b) acts through NO in isolated tubules and thus presumably through stimulation of a tubule NO synthase (NOS). We show here by reverse-transcription polymerase chain reaction that Drosophila NOS (dNOS) is expressed in Malpighian tubules. Biochemical assays of NOS activity in whole tubules show that CAP(2b) significantly stimulates NOS activity. Additionally, fluid secretion and cyclic nucleotide assays show that CAP(2b)-induced elevation of intracellular cGMP levels and fluid secretion rates are dependent on the activation of a soluble guanylate cyclase. Treatment of tubules with a specific NOS inhibitor abolishes the CAP(2b)-induced rise in intracellular cGMP levels. These data indicate that CAP(2b) stimulates NOS and, therefore, endogenous NO production, which, in turn, stimulates a soluble guanylate cyclase. This is the first demonstration of stimulation of an endogenous NOS by a defined peptide in Drosophila.
AB - Activation of the nitric oxide (NO) and guanosine 3',5'-cyclic monophosphate (cGMP) signaling pathway stimulates fluid secretion by the Drosophila melanogaster Malpighian tubule. The neuropeptide cardioacceleratory peptide 2b (CAP(2b)) has been previously shown to stimulate fluid secretion in this epithelium by elevating intracellular cGMP levels. Therefore, it was of interest to investigate if CAP(2b) acts through NO in isolated tubules and thus presumably through stimulation of a tubule NO synthase (NOS). We show here by reverse-transcription polymerase chain reaction that Drosophila NOS (dNOS) is expressed in Malpighian tubules. Biochemical assays of NOS activity in whole tubules show that CAP(2b) significantly stimulates NOS activity. Additionally, fluid secretion and cyclic nucleotide assays show that CAP(2b)-induced elevation of intracellular cGMP levels and fluid secretion rates are dependent on the activation of a soluble guanylate cyclase. Treatment of tubules with a specific NOS inhibitor abolishes the CAP(2b)-induced rise in intracellular cGMP levels. These data indicate that CAP(2b) stimulates NOS and, therefore, endogenous NO production, which, in turn, stimulates a soluble guanylate cyclase. This is the first demonstration of stimulation of an endogenous NOS by a defined peptide in Drosophila.
KW - Cardioacceleratory peptide 2b
KW - Nitric oxide synthase
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U2 - 10.1152/ajpregu.1997.273.2.r823
DO - 10.1152/ajpregu.1997.273.2.r823
M3 - Article
C2 - 9277574
AN - SCOPUS:0030846675
SN - 0363-6119
VL - 273
SP - R823-R827
JO - American Journal of Physiology - Regulatory Integrative and Comparative Physiology
JF - American Journal of Physiology - Regulatory Integrative and Comparative Physiology
IS - 2 42-2
ER -