Type A allatostatins from Drosophila melanogaster and Diplotera puncata activate two Drosophila allatostatin receptors, DAR-1 and DAR-2, expressed in CHO cells.
The type-A allatostatins A (AST-A) are a group of insect peptides with a common C-terminal motif Y/FXFGL-NH(2). The existence of at least four putative type A Drosophila melanogaster ASTs (called type A drostatins or DST-As) has been predicted from the sequence of a recently cloned DST-A preprohormone [C. Lenz et al. (2000) Biochem. Biophys. Res. Commun. 273, 126-1131]. SRPYSFGL-NH(2), (DST-3A), the only DST isolated from Drosophila so far, activated the first cloned DST-A GPCR (DAR-1) [N. Birgül et al. (1999) EMBO J. 18, 5892-5900]. A newly cloned orphan Dm GPCR, which shares 47% overall and 60% transmembrane region sequence identity with DAR-1, was classified as a second putative Dm DST-A receptor (DAR-2) [C. Lenz et al. (2000) Biochem. Biophys. Res. Commun. 273, 571-577]. Although activation of DAR-2 by DSTs has been postulated, no experimental evidence for that has been presented to date. In this study, we expressed both DAR-1 and DAR-2 in CHO cells and used a GTPgammaS and a Ca(2+) mobilization assay for pharmacological evaluation of the receptors. Synthetically prepared DST-As, as well as selected Diplotera punctata (cockroach) ASTs, activated DAR-1 and DAR-2 in both functional assays indicating ligand redundancy and cross species activity. Cell pretreatment with pertussis toxin led to some differences in the nature and magnitude of signaling pathways at the DAR-1 and DAR-2 receptors, suggesting possible differential coupling to cellular effector system(s) and distinct biological functions of each receptor in vivo.
Larsen
M J
MJ
Animal Health Discovery Research, Pharmacia, Kalamazoo, Michigan 49001, USA.
Burton
K J
KJ
Zantello
M R
MR
Smith
V G
VG
Lowery
D L
DL
Kubiak
T M
TM
D020816:Amino Acid Motifs; D000818:Animals; D016466:CHO Cells; D002118:Calcium / Q000378:metabolism; D003001:Cloning, Molecular; D006224:Cricetinae; D004175:Diptera; D004305:Dose-Response Relationship, Drug; D029721:Drosophila Proteins; D004331:Drosophila melanogaster; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000378:metabolism; D019476:Insect Proteins; D007700:Kinetics; D008024:Ligands; D009479:Neuropeptides / Q000737:chemistry* / Q000378:metabolism*; D037342:Pertussis Toxin; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011956:Receptors, Cell Surface / Q000737:chemistry* / Q000378:metabolism*; D043562:Receptors, G-Protein-Coupled; D018013:Receptors, Neuropeptide; D015398:Signal Transduction; D013997:Time Factors; D014162:Transfection; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
C096426:AstA-R1 protein, Drosophila; C543272:AstA-R2 protein, Drosophila; D029721:Drosophila Proteins; D019476:Insect Proteins; D008024:Ligands; D009479:Neuropeptides; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; D018013:Receptors, Neuropeptide; D010566:Virulence Factors, Bordetella; C076523:allatostatin; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D037342:Pertussis Toxin; D002118:Calcium