Patterns of N-acetyl-beta-glucosaminidase isoenzymes in the epidermis and hepatopancreas and induction of N-acetyl-beta-glucosaminidase activity by 20-hydroxyecdysone in the fiddler crab, Uca pugilator.
A new staining method for detection of N-acetyl-beta-glucosaminidase on denaturing SDS polyacrylamide gels was developed. The isoenzyme pattern of N-acetyl-beta-glucosaminidase in the epidermis of the fiddler crab, Uca pugilator, is different from that in the hepatopancreas. Two isoforms of N-acetyl-beta-glucosaminidase, with molecular weights of 89 and 45.6 kDa, are present in the hepatopancreas while there is only one form of N-acetyl-beta-glucosaminidase, 89 kDa, in the epidermis. No sexual dimorphism was found in these patterns of N-acetyl-beta-glucosaminidase isoenzymes. The characteristic isoenzyme patterns in the epidermis and hepatopancreas occurred consistently throughout the molting cycle. Injections of the molting hormone, 20-hydroxyecdysone, at 25 microg/g live weight, into crabs in premolt substage D1, significantly increased N-acetyl-beta-glucosaminidase activity in the epidermis by 86%. Since only one form of N-acetyl-beta-glucosaminidase, 89 kDa, is present in the epidermis, the elevation in epidermal enzymatic activity after 20-hydroxyecdysone administration is entirely accounted for by this N-acetyl-beta-glucosaminidase isoenzyme. The results reported herein are the first direct evidence that in a crustacean N-acetyl-beta-glucosaminidase activity is regulated by the steroid molting hormone.
Zou
E
E
Institute of Toxicology and Environmental Health, University of California, Davis 95616, USA.
Fingerman
M
M
D000118:Acetylglucosaminidase / Q000032:analysis / Q000096:biosynthesis* / Q000187:drug effects; D000818:Animals; D003386:Brachyura / Q000187:drug effects* / Q000201:enzymology; D004064:Digestive System / Q000187:drug effects* / Q000201:enzymology; D004441:Ecdysterone / Q000494:pharmacology*; D004591:Electrophoresis, Polyacrylamide Gel; D004790:Enzyme Induction; D004817:Epidermis / Q000187:drug effects* / Q000201:enzymology; D007447:Invertebrate Hormones / Q000494:pharmacology; D007527:Isoenzymes / Q000032:analysis / Q000096:biosynthesis* / Q000187:drug effects; D013194:Staining and Labeling / Q000379:methods
D007447:Invertebrate Hormones; D007527:Isoenzymes; D004441:Ecdysterone; D000118:Acetylglucosaminidase