Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Extracellular peptidases of imaginal discs of Drosophila melanogaster.
AU - Wilson, Claire L.
AU - Shirras, Alan D.
AU - Isaac, R. Elwyn
PY - 2002/11
Y1 - 2002/11
N2 - The imaginal discs of Drosophila melanogaster give rise to the adult epidermis during metamorphosis. During this developmental period several peptidase genes are expressed in disc cells, but there is a paucity of biochemical information regarding substrate specificity. We have used peptides and peptidyl 7-amino-4-methylcoumarin (AMC) substrates to detect several peptidases either positioned on the surface of wing discs or secreted by the imaginal cells. Using [Leu5]enkephalin as a substrate, a captopril sensitive dipeptidyl carboxypeptidase (angiotensin I-converting enzyme) and an amastatin-sensitive aminopeptidase were detected as prominent activities associated with intact discs. The formation of [Leu5]enkephalin-derived Phe was attributed to the concerted action of the D. melanogaster angiotensin I-converting enzyme (Ance) and a dipeptidase. The disc Ance also showed endopeptidic activity towards locust tachykinin-1 (LomTK-I) by cleaving the Gly–Val peptide bond, but this enzyme was not the sole endopeptidase activity associated with discs. Complete inhibition of the endopeptidic hydrolysis of the LomTK-1 by a disc homogenate required a combination of captopril and the neprilysin inhibitor, phosphoramidon, providing biochemical evidence for a neprilysin-like peptidase, in addition to Ance, in imaginal discs of D. melanogaster. Peptidyl AMC substrates for furin, prohormone convertase and tryptase provided evidence for trypsin-like serine endopeptidases in addition to the metalloendopeptidases. We conclude that imaginal discs are endowed with a variety of peptidases from different families that together are capable of hydrolyzing a broad range of peptides and proteins. Some of these peptidases might be responsible for the metabolic activation/inactivation of signaling peptides, as well as being involved in the production of dipeptides and free amino acids required for protein synthesis and osmotic balance during adult morphogenesis.
AB - The imaginal discs of Drosophila melanogaster give rise to the adult epidermis during metamorphosis. During this developmental period several peptidase genes are expressed in disc cells, but there is a paucity of biochemical information regarding substrate specificity. We have used peptides and peptidyl 7-amino-4-methylcoumarin (AMC) substrates to detect several peptidases either positioned on the surface of wing discs or secreted by the imaginal cells. Using [Leu5]enkephalin as a substrate, a captopril sensitive dipeptidyl carboxypeptidase (angiotensin I-converting enzyme) and an amastatin-sensitive aminopeptidase were detected as prominent activities associated with intact discs. The formation of [Leu5]enkephalin-derived Phe was attributed to the concerted action of the D. melanogaster angiotensin I-converting enzyme (Ance) and a dipeptidase. The disc Ance also showed endopeptidic activity towards locust tachykinin-1 (LomTK-I) by cleaving the Gly–Val peptide bond, but this enzyme was not the sole endopeptidase activity associated with discs. Complete inhibition of the endopeptidic hydrolysis of the LomTK-1 by a disc homogenate required a combination of captopril and the neprilysin inhibitor, phosphoramidon, providing biochemical evidence for a neprilysin-like peptidase, in addition to Ance, in imaginal discs of D. melanogaster. Peptidyl AMC substrates for furin, prohormone convertase and tryptase provided evidence for trypsin-like serine endopeptidases in addition to the metalloendopeptidases. We conclude that imaginal discs are endowed with a variety of peptidases from different families that together are capable of hydrolyzing a broad range of peptides and proteins. Some of these peptidases might be responsible for the metabolic activation/inactivation of signaling peptides, as well as being involved in the production of dipeptides and free amino acids required for protein synthesis and osmotic balance during adult morphogenesis.
KW - Peptide metabolism
KW - Angiotensin I-converting enzyme
KW - Aminopeptidase
KW - Dipeptidase
KW - Dipeptidyl peptidase IV
KW - Neprilysin
U2 - 10.1016/S0196-9781(02)00188-2
DO - 10.1016/S0196-9781(02)00188-2
M3 - Journal article
VL - 23
SP - 2007
EP - 2014
JO - Peptides
JF - Peptides
SN - 0196-9781
IS - 11
ER -