The β1 subunit of Na+/K+-ATPase interacts with BKCa channels and affects their steady-state expression on the cell surface

Edited by Maurice Montal

Received 27 July 2009; received in revised form 21 August 2009; accepted 24 August 2009. published online 01 September 2009.

Abstract

Large conductance Ca2+-activated K+ channels (BKCa) encoded by the Slo1 gene play a role in the physiological regulation of many cell types. Here, we show that the β1 subunit of Na+/K+-ATPase (NKβ1) interacts with the cytoplasmic COOH-terminal region of Slo1 proteins. Reduced expression of endogenous NKβ1 markedly inhibits evoked BKCa currents with no apparent effect on their gating. In addition, NKβ1 down-regulated cells show decreased density of Slo1 subunits on the cell surface.

Structured summary

MINT-7260438, MINT-7260555: Slo1 (uniprotkb:Q8AYS8) physically interacts (MI:0915) with NKbeta1 (uniprotkb:P08251) by anti bait coimmunoprecipitation (MI:0006)

MINT-7260587, MINT-7260606, MINT-7260619, MINT-7260632: Slo1 (uniprotkb:Q08460) physically interacts (MI:0915) with NKbeta 1 (uniprotkb:P08251) by pull down (MI:0416)

MINT-7260570: NKbeta1 (uniprotkb:P08251) and Slo1 (uniprotkb:Q8AYS8) colocalize (MI:0403) by fluorescence microscopy (MI:0416)

MINT-7260414: Slo1 (uniprotkb:Q08460) physically interacts (MI:0915) with NKbeta1 (uniprotkb:P08251) by two hybrid (MI:0018)

Abbreviations: CG, ciliary ganglion, NKβ1, Na+/K+-ATPase β1 subunit, NKα, Na+/K+-ATPase α-subunit, BKCa, large conductance Ca2+-activated K+ channels

Keywords: Potassium channel, Trafficking, Ion transporter, ATPase, KCNMA1

Department of Biology and Biochemistry, University of Houston, 4800 Calhoun, Houston, TX 77204-5001, United States

Corresponding author. Fax: +1 713 743 2632.

PII: S0014-5793(09)00668-1

doi:10.1016/j.febslet.2009.08.039

2 of 36