Cation transport coupled to ATP hydrolysis by the (Na, K)-ATPase

An integrated, animated model

Authors

  • Francisco A. Leone,

    Corresponding author
    1. Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, 14040-901 Ribeirão Preto, São Paulo, Brasil
    • Departamento de Química, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto/Universidade de São Paulo, 14040-901 Ribeirão Preto, São Paulo, Brasil
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    • Tel.: +55 16 3602 3668; Fax: +55 16 3602 4838

  • Rosa P. M. Furriel,

    1. Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, 14040-901 Ribeirão Preto, São Paulo, Brasil
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  • John C. McNamara,

    1. Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, 14040-901 Ribeirão Preto, São Paulo, Brasil
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  • Jean D. Horisberger,

    1. Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland
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    • Deceased, July 1, 2009.

  • Ivana A. Borin

    1. Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, 14040-901 Ribeirão Preto, São Paulo, Brasil
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  • This work is supported by Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), and Instituto Nacional de Ciência e Tecnologia (INCT) Adapta/Fundação de Amparo à Pesquisa do Estado do Amazonas (FAPEAM, No. 573976/2008-2)

Abstract

An Adobe® animation is presented for use in undergraduate Biochemistry courses, illustrating the mechanism of Na+ and K+ translocation coupled to ATP hydrolysis by the (Na, K)-ATPase, a P2c-type ATPase, or ATP-powered ion pump that actively translocates cations across plasma membranes. The enzyme is also known as an E1/E2-ATPase as it undergoes conformational changes between the E1 and E2 forms during the pumping cycle, altering the affinity and accessibility of the transmembrane ion-binding sites. The animation is based on Horisberger's scheme that incorporates the most recent significant findings to have improved our understanding of the (Na, K)-ATPase structure–function relationship. The movements of the various domains within the (Na, K)-ATPase α-subunit illustrate the conformational changes that occur during Na+ and K+ translocation across the membrane and emphasize involvement of the actuator, nucleotide, and phosphorylation domains, that is, the “core engine” of the pump, with respect to ATP binding, cation transport, and ADP and Pi release.

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