Modulation by K+ Plus NH4+ of microsomal (Na+, K+)-ATPase activity in selected ontogenetic stages of the diadromous river shrimp Macrobrachium amazonicum (Decapoda, Palaemonidae)

Francisco A Leone; Thais M S Bezerra; Daniela P Garçon; Malson N Lucena; Marcelo R Pinto; Carlos F L Fontes; John C McNamara

doi:10.1371/journal.pone.0089625

Modulation by K+ Plus NH4+ of microsomal (Na+, K+)-ATPase activity in selected ontogenetic stages of the diadromous river shrimp Macrobrachium amazonicum (Decapoda, Palaemonidae)

PLoS One. 2014 Feb 21;9(2):e89625. doi: 10.1371/journal.pone.0089625. eCollection 2014.

Authors

Francisco A Leone¹, Thais M S Bezerra¹, Daniela P Garçon², Malson N Lucena³, Marcelo R Pinto¹, Carlos F L Fontes⁴, John C McNamara⁵

Affiliations

¹ Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil.
² Departamento de Biologia Molecular, Centro de Ciências Exatas e da Natureza, Universidade Federal da Paraíba, João Pessoa, PB, Brasil.
³ Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil.
⁴ Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brasil.
⁵ Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil.

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 ≈ 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 α-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.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Ammonium Compounds / metabolism*
Animals
Arthropod Proteins / metabolism*
Female
Gills / enzymology
Kinetics
Male
Microsomes / enzymology*
Osmoregulation
Ouabain / pharmacology
Palaemonidae / enzymology*
Potassium / physiology*
Protein Subunits / metabolism
Protein Transport
Rivers
Sodium-Potassium-Exchanging ATPase / antagonists & inhibitors
Sodium-Potassium-Exchanging ATPase / metabolism*

Substances

Ammonium Compounds
Arthropod Proteins
Protein Subunits
Ouabain
Sodium-Potassium-Exchanging ATPase
Potassium

Grants and funding

This investigation was supported by research grants from the Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP 2010/17534-0) (www.fapesp.br); Conselho de Desenvolvimento Científico e Tecnológico (CNPq) (wwww.cnpq.br); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) (www.capes.gov.br) and Instituto Nacional de Ciência e Tecnologia (INCT) Adapta/Fundação de Amparo à Pesquisa do Estado do Amazonas (FAPEAM 573976/2008-2) ([email protected]). TMBS and MNL received undergraduate scholarships from CNPq (566167/2008-5) and FAPESP (2010/16115-3), respectively. DPG and MRP received post-doctoral scholarships from FAPESP (2010/06395-9) and CNPq (560501/2010-2), respectively. FAL (302776/2012-7), JCM (300662/2009-2) and CFLF (307559/2011-4) received research scholarships from CNPq. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.