These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Selective basolateral localization of overexpressed Na-K-ATPase beta1- and beta2- subunits is disrupted by butryate treatment of MDCK cells.
    Author: Laughery MD, Clifford RJ, Chi Y, Kaplan JH.
    Journal: Am J Physiol Renal Physiol; 2007 Jun; 292(6):F1718-25. PubMed ID: 17344187.
    Abstract:
    The exclusive basolateral localization of the Na-K-ATPase in kidney epithelium is a critical aspect of nephron function. It has been suggested that mislocalized delivery of the Na-K-ATPase to the apical surface in autosomal dominant polycystic kidney disease (ADPKD) is due to the inappropriate expression of an alternative isoform of the beta-subunit, the beta(2)-isoform. It has been reported that heterologous expression of this beta(2)-isoform in Madin-Darby canine kidney (MDCK) cells results in apical delivery of the Na-K-ATPase. We created a MDCK cell line containing a tetracycline-inducible promoter and expressed either myc-tagged beta(2)- or flag-tagged beta(1)-subunits to study the surface localization of these beta-subunit isoforms in polarized monolayers. We find that the beta(2)-isoform is targeted to the basolateral surface of the plasma membrane in a polarization pattern indistinguishable from the beta(1)-isoform. However, inclusion of butyrate in the growth medium leads to upregulation of overexpressed beta(1)- or beta(2)-subunits and to their appearance at the apical surface. The beta(2)-isoform expressed in MDCK cells does not assemble into alpha(1)beta(2) heterodimers with the endogenous alpha(1). Our findings demonstrate that expression of the beta(2)-isoform does not lead to apical localization of the Na-K-ATPase in MDCK cells and provides evidence for an unexpected effect of butyrate on the trafficking of Na pump subunits.
    [Abstract] [Full Text] [Related] [New Search]