title: Interplay between acid phosphatase and cysteine proteases in mediating vitellin degradation during early embryogenesis of Periplaneta americana.
abstract: In this work, we characterized the activities of two classes of proteases and AcP during early embryogenesis of Periplaneta americana. AcP activity was first detected at day 6 and reached a maximum level at day 10 of development. Using phosphoamino acids, phosphatase activity was shown to be directed only against phosphotyrosine at day 6 while at day 10 it was also active against phosphoserine. In parallel, two classes of proteases were detected and located within yolk granules: a clan CA-cysteine protease, which was inhibited by E-64, insensitive to CA 074 and activated by acidic pH at day 3; and a neutral serine protease, which was inhibited by aprotinin at day 6. Assays of vitellin (Vt) degradation evidenced that incubations at neutral pH induced slight proteolysis, while the incubations at acidic pH did not result in Vt degradation. However, pre-incubations of Vt with AcP increased the levels of Vt acidic proteolysis and this could be inhibited by the addition of phosphatase inhibitors. On the other hand, the same pre-incubations showed no effects on the profile of degradation at neutral pH. We propose that AcP and cysteine protease cooperate to assure Vt breakdown during early embryogenesis of P. americana.
authors.affiliation: Laboratório de Entomologia Médica, Programa de Parasitologia e Biologia Celular, Instituto de Biofísica Carlos Chagas Filho, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Cidade Universitária, Rio de Janeiro, RJ, Brazil.
authors.forename: Danielle M P
authors.initials: DM
authors.lastname: Oliveira
authors.forename: Isabela B
authors.initials: IB
authors.lastname: Ramos
authors.forename: Flavia C G
authors.initials: FC
authors.lastname: Reis
authors.forename: Ana P C A
authors.initials: AP
authors.lastname: Lima
authors.forename: Ednildo A
authors.initials: EA
authors.lastname: Machado
mesh_terms: D000135:Acid Phosphatase / Q000378:metabolism*; D000367:Age Factors; D000818:Animals; D003374:Coumarins; D003546:Cysteine Endopeptidases / Q000378:metabolism*; D004151:Dipeptides; D004527:Egg Proteins / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D006863:Hydrogen-Ion Concentration; D010526:Periplaneta / Q000196:embryology* / Q000378:metabolism; D019606:Phosphoamino Acids / Q000378:metabolism; D047048:Vitellins / Q000378:metabolism*
chemical_list: D003374:Coumarins; D004151:Dipeptides; D004527:Egg Proteins; D019606:Phosphoamino Acids; D047048:Vitellins; C021159:benzyloxycarbonyl-phenylalanylarginine-4-methylcoumaryl-7-amide; D000135:Acid Phosphatase; D003546:Cysteine Endopeptidases