Short- and long-term, salinity-induced modulation of V-ATPase activity in the posterior gills of the true freshwater crab, Dilocarcinus pagei (Brachyura, Trichodactylidae)

Autor(es)

Silva Firmino, Kelly Cristina ^[1] ; Faleiros, Rogerio Oliveira ^[2] ; Masui, Douglas Chodi ^{[1, 2]} ; McNamara, John Campbell ^[2] ; Melo Furriel, Rosa Prazeres ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Quim, Fac Filosofia Ciencias & Letras Ribeirao Preto, BR-14040901 Sao Paulo - Brazil

^[2] Univ Sao Paulo, Dept Biol, Fac Filosofia Ciencias & Letras Ribeirao Preto, BR-14040901 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY B-BIOCHEMISTRY & MOLECULAR BIOLOGY; v. 160, n. 1, p. 24-31, SEP 2011.
• Citações Web of Science: 14

Resumo

To better understand the biochemical mechanisms underlying anisosmotic extracellular regulation in the freshwater Brachyura, we kinetically characterized the V-ATPase from the posterior gills of Dilocarcinus pagei, acclimated for 10 days to salinities up to 21%.. Specific activity was highest in fresh water (26.5 +/- 2.1 U mg(-1)), decreasing in 5 parts per thousand to 21 parts per thousand, attaining 3-fold less at 15 parts per thousand. Apparent affinities for ATP and Mg(2+) respectively increased 3.2- and 2-fold at 10 parts per thousand, suggesting expression of different isoenzymes. In a 240-h time-course study of exposure to 21%., maximum specific activity decreased 2.5- to 4-fold within 1 to 24 h while apparent affinities for ATP and Mg(2+) respectively increased by 12-fold within 24 h and 2.4-fold after 1 h, unchanged thereafter. K(I) for bafilomycin A(1) decreased 150-fold after 1 h, remaining constant up to 120 h. This is the first kinetic analysis of V-ATPase specific activity in crustacean gills during salinity acclimation. Our findings indicate active gill Cl(-) uptake by D. pagei in fresh water, and short- and long-term down-regulation of V-ATPase-driven ion uptake processes during salinity exposure, aiding in comprehension of the biochemical adaptations underpinning the establishment of the Brachyura in fresh water. (C) 2011 Elsevier Inc. All rights reserved. (AU)

• Processo FAPESP: 07/04870-9 - Estratégias fisiológicas adaptativas nos crustáceos: a invasão da água doce e as bases moleculares e estruturais da osmorregulação
• Beneficiário: John Campbell McNamara
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 08/57830-7 - Osmorregulacao e excrecao de amonia em crustaceos decapodes
• Beneficiário: Rosa dos Prazeres Melo Furriel
• Modalidade de apoio: Auxílio à Pesquisa - Regular