Advanced search
Start date
Betweenand
Related content
(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Modulation By K+ Plus NH4+ of Microsomal (Na+, K+)ATPase Activity in Selected Ontogenetic Stages of the Diadromous River Shrimp Macrobrachium amazonicum (Decapoda, Palaemonidae)

Full text
Author(s):
Leone, Francisco A. [1] ; Bezerra, Thais M. S. [1] ; Garcon, Daniela P. [2] ; Lucena, Malson N. [3] ; Pinto, Marcelo R. [1] ; Fontes, Carlos F. L. [4] ; McNamara, John C. [5]
Total Authors: 7
Affiliation:
[1] Univ Sao Paulo, Fac Filosofia Ciencias & Letras Ribeirao Preto, Dept Quim, Ribeirao Preto, SP - Brazil
[2] Univ Fed Paraiba, Ctr Ciencias Exatas & Natureza, Dept Biol Mol, BR-58059900 Joao Pessoa, Paraiba - Brazil
[3] Univ Sao Paulo, Fac Med Ribeirao Preto, Dept Bioquim & Imunol, BR-14049 Ribeirao Preto, SP - Brazil
[4] Univ Fed Rio de Janeiro, Inst Bioquim Med, Rio De Janeiro, RJ - Brazil
[5] Univ Sao Paulo, Fac Filosofia Ciencias & Letras Ribeirao Preto, Dept Biol, Ribeirao Preto, SP - Brazil
Total Affiliations: 5
Document type: Journal article
Source: PLoS One; v. 9, n. 2 FEB 21 2014.
Web of Science Citations: 12
Abstract

We investigate the synergistic stimulation by K+ plus NH4+ of (Na+, K+)-ATPase activity in microsomal preparations of whole zoea I and decapodid III, and in juvenile and adult river shrimp gills. Modulation of (Na+, K+)-ATPase activity is ontogenetic stage-specific, and particularly distinct between juveniles and adults. Although both gill enzymes exhibit two different sites for K+ and NH4+ binding, in the juvenile enzyme, these two sites are equivalent: binding by both ions results in slightly stimulated activity compared to that of a single ionic species. In the adult enzyme, the sites are not equivalent: when one ion occupies its specific binding site, (Na+, K+)-ATPase activity is stimulated synergistically by approximate to 50% on binding of the complementary ion. Immunolocalization reveals the enzyme to be distributed predominantly throughout the intralamellar septum in the gill lamellae of juveniles and adults. Western blot analyses demonstrate a single immunoreactive band, suggesting a single (Na+, K+)-ATPase alpha-subunit isoform that is distributed into different density membrane fractions, independently of ontogenetic stage. We propose a model for the modulation by K+ and NH4+ of gill (Na+, K+)-ATPase activity. These findings suggest that the gill enzyme may be regulated by NH4+ during ontogenetic development in M. amazonicum. (AU)

FAPESP's process: 10/17534-0 - Role of (Na,K)-ATPase in osmoregulation and excretion of ammonium ions in euryhaline crustaceans: identification and influence of FXYD2 on the regulation of gill (Na,K)-ATPase of the crab Callinectes danae
Grantee:Francisco de Assis Leone
Support Opportunities: Regular Research Grants