QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online 6 October 2009
doi: 10.1242/jcs.046953

This Article Figures Only Full Text Full Text (PDF) Supplementary Material All Versions of this Article: jcs.046953v1 122/21/3915    most recent Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Lecuona, E. Articles by Sznajder, J. I. PubMed PubMed Citation Articles by Lecuona, E. Articles by Sznajder, J. I. Social Bookmarking                         What's this?

Myosin-Va restrains the trafficking of Na⁺/K⁺-ATPase-containing vesicles in alveolar epithelial cells

¹ Division of Pulmonary and Critical Care Medicine, Department of Medicine, Northwestern University, Chicago, IL 60611, USA
² Department of Cell and Molecular Biology, Northwestern University, Chicago, IL 60611, USA
³ Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA
⁴ Institute of Protein Research, Russian Academy of Sciences, Moscow 119988, Russia

^* Author for correspondence (e-lecuona{at}northwestern.edu)

Accepted 3 August 2009

Stimulation of Na⁺/K⁺-ATPase activity in alveolar epithelial cells by cAMP involves its recruitment from intracellular compartments to the plasma membrane. Here, we studied the role of the actin molecular motor myosin-V in this process. We provide evidence that, in alveolar epithelial cells, cAMP promotes Na⁺/K⁺-ATPase recruitment to the plasma membrane by increasing the average speed of Na⁺/K⁺-ATPase-containing vesicles moving to the cell periphery. We found that three isoforms of myosin-V are expressed in alveolar epithelial cells; however, only myosin-Va and Vc colocalized with the Na⁺/K⁺-ATPase in intracellular membrane fractions. Overexpression of dominant-negative myosin-Va or knockdown with specific shRNA increased the average speed and distance traveled by the Na⁺/K⁺-ATPase-containing vesicles, as well as the Na⁺/K⁺-ATPase activity and protein abundance at the plasma membrane to similar levels as those observed with cAMP stimulation. These data show that myosin-Va has a role in restraining Na⁺/K⁺-ATPase-containing vesicles within intracellular pools and that this restrain is released after stimulation by cAMP allowing the recruitment of the Na⁺/K⁺-ATPase to the plasma membrane and thus increased activity.

Key words: Na⁺/K⁺-ATPase, Myosin-V, Traffic

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?