Regulation of Plasma Membrane V-ATPase Activity by Dissociation of Peripheral Subunits

doi:10.1074/jbc.270.10.5649

Regulation of Plasma Membrane V-ATPase Activity by Dissociation of Peripheral Subunits (*)

From the (1)Department of Cell Biology, University of Glasgow, Glasgow G12 8QQ, United Kingdom,
(2)ZENECA Agrochemicals Jeallol's Hill Research Station, Bracknell, BERKS RG12 6EY, United Kingdom, and the
(3)Zoological Institute, University of Munich, D-80021 Munich, Federal Republic of Germany

^§ To whom correspondence may be addressed. Tel.: 44-41-330-4616; Fax: 44-41-330-4501.
^¶ To whom correspondence may be addressed:
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Tel.: 49-89-5902-325; Fax: 49-89-5902-450.

Abstract

The plasma membrane V-ATPase of Manduca sexta larval midgut is an electrogenic proton pump located in goblet cell apical membranes (GCAM); it energizes, by the voltage component of its proton motive force, an electrophoretic K/nH antiport and thus K secretion (Wieczorek, H., Putzenlechner, M., Zeiske, W., and Klein, U.(1991) J. Biol Chem. 266, 15340-15347). Midgut transepithelial voltage, indicating net active K transport, was found to be more than 100 mV during intermoult stages but was abolished during moulting. Simultaneously, ATP hydrolysis and ATP-dependent proton transport in GCAM vesicles were found to be reduced to 10-15% of the intermoult level. Immunocytochemistry of midgut cryosections as well as SDS-polyacrylamide gel electrophoresis and immunoblots of GCAM demonstrated that loss of ATPase activity paralleled the disappearance of specific subunits. The subunits missing were those considered to compose the peripheral V₁ sector, whereas the membrane integral V₀ subunits remained in the GCAM of moulting larvae. The results provide, for the first time, evidence that a V-ATPase activity can be controlled in vivo by the loss of the peripheral V₁ domain.

Footnotes

↵* This work was supported by a Science Research Council CASE award, Medical Research Council Grant G9120579CB, German Research Foundation Grant Wi 698, European Economic Community Grant SC1*-CT90-0480, and National Institutes of Health Grant AI22444. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore by hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

The nucleotide sequence(s) reported in this paper has been submitted to the GenBank™/EMBL Data Bank with accession number(s) Z26918[GenBank].

ZENECA Agrochemicals in the U.K. is part of ZENECA Ltd., registered in England No. 2710846.
↵¹A. Lepier and H. Wieczorek, unpublished observations.
² The abbreviations used are:

TEV

transepithelial voltage

GCAM

goblet cell apical membranes

MOPS

3-(N-morpholino)propanesulfonic acid.
↵³U. Klein, M. Timme, F. J. S. Novak, A. Lepier, W. R. Harvey, and H. Wieczorek, unpublished results.
- Received August 16, 1994.
- Revision received October 27, 1994.