Introduction: A Close Look at an Ion Pump

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  • P1: VANDOR/GDWJournal of Bioenergetics and Biomembranes (JOBB) PP240-343050 August 9, 2001 17:8 Style file version Nov. 07, 2000

    Journal of Bioenergetics and Biomembranes, Vol. 33, No. 5, October 2001 ( c 2001)

    INTRODUCTORY OVERVIEW

    Introduction: A Close Look at an Ion Pump

    Jack Kaplan1

    The Na,K-ATPase or sodium pump is a vital player inthe efficient functioning of all of the organs of the humanbody. This assertion helps explain why since its discov-ery in 1957 (for which J.C. Skou, in 1998, shared theNobel Prize in Chemistry), the Na,K-ATPase has beenthe object of study for several generations of biochemists,physiologists, biophysicists, and clinical scientists. Its re-lationship to other transport proteins has become clearerand its place in a superfamily of P-type ATPases has beenrevealed through the analysis of continually increasinggenomic data bases.

    The recent demonstrations of the exquisite operationof the F0F1-ATPase, at a mechanistic and structural level(for which Paul Boyer and John Walker shared the sameNobel Prize) revealed a biological nanomachine, which

    1 Department of Biochemistry & Molecular Biology, Oregon HealthSciences University, Portland, Oregon 97201-3098. e-mail: kaplanj@ohsu.esu

    seemed familiar from our knowledge of how other rotarymotors work at an everyday macro level. From what wealready know about how P-type ATPases work, and fromwhat is revealed by the high-resolution structure of the Capump, such aesthetically pleasing analogies will be lessobvious for these active transport proteins. The importantstructural changes that occur during the working cycleof these pumps are not yet apparent and seem likely toinvolve combinations of interdomain motions and subtlerealignments of intramembrane structures.

    The eight minireviews on the Na,K-ATPase appear-ing in this issue describe current ideas on how the sodiumpump works and how it is regulated. They bring togetherthe views of an international group of active contributorsto this area and provide an up-to-date snapshot of what isknown about this protein from a variety of viewpoints. Ihope that this compendium will provide a useful sourceof information, but, more importantly, serve as a catalystfor new ideas and experiments.

    3650145-479X/01/1000-0365$19.50/0 C 2001 Plenum Publishing Corporation