Molting cycle-dependent expression of CYP4C15, a cytochrome P450 enzyme putatively involved in ecdysteroidogenesis in the crayfish, Orconectes limosus.
A cytochrome P450 enzyme cDNA (CYP4C15) has been previously cloned from a cDNA library of crayfish steroidogenic glands (Y-organs). The conceptual translation of the CYP4C15 cDNA sequence was analyzed for regions of putative high antigenicity and a mixture of two synthetic peptides was chosen for the production of a specific polyclonal antibody. Western blot analysis on Y-organ subcellular fractions indicated an endoplasmic reticulum location of CYP4C15, in agreement with the structural feature of the predicted protein, i.e. the presence of a hydrophobic N-terminal segment. The protein is only expressed in Y-organs, thus showing a similar distribution to the corresponding mRNA. From this tissue specific expression, it has been postulated that CYP4C15 would play a role in ecdysteroid biosynthesis rather than detoxification and the variations of its expression during a molt cycle were carefully examined. CYP4C15 is not detectable in intermolt animals, expression levels are maximal during early premolt and decrease during late premolt. The results are discussed in relation to the variations of hemolymphatic ecdysteroid titers and steroidogenic capacities of the Y-organs during the molt cycle.
Aragon
Santiago
S
Université Pierre et Marie Curie, Laboratoire Endocrinologie Moleculaire et Evolution, Bât A, Seme etage, Case 29, 7 Quai Saint-Bernard, F-75005 Paris, France.
Claudinot
Stéphanie
S
Blais
Catherine
C
Maïbèche
Martine
M
Dauphin-Villemant
Chantal
C
D000595:Amino Acid Sequence; D000818:Animals; D003400:Astacoidea / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics*; D000072470:Cytochrome P450 Family 4; D004441:Ecdysterone / Q000096:biosynthesis*; D015870:Gene Expression; D008969:Molecular Sequence Data; D018978:Molting / Q000502:physiology; D009479:Neuropeptides / Q000378:metabolism; D013347:Subcellular Fractions; D014018:Tissue Distribution
D009479:Neuropeptides; C101529:molt-inhibiting hormone, crayfish; D004441:Ecdysterone; D003577:Cytochrome P-450 Enzyme System; D000072470:Cytochrome P450 Family 4; C400365:cytochrome P450 CYP4C15 (crayfish)