{alpha}1-AMP-Activated Protein Kinase Regulates Hypoxia-Induced Na,K-ATPase Endocytosis via Direct Phosphorylation of Protein Kinase C{zeta}

doi:10.1128/MCB.00054-09

This Article

	Full Text
	Full Text (PDF)
	Alert me when this article is cited
	Alert me if a correction is posted
	Citation Map

Services

	E-mail 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
	Reprints and Permissions
	Copyright Information
	Books from ASM Press
	MicrobeWorld

Citing Articles

	Citing Articles via HighWire
	Citing Articles via Google Scholar

Google Scholar

	Articles by Gusarova, G. A.
	Articles by Sznajder, J. I.
	Search for Related Content

PubMed

	PubMed Citation
	Articles by Gusarova, G. A.
	Articles by Sznajder, J. I.

${alpha}$ 1-AMP-Activated Protein Kinase Regulates Hypoxia-Induced Na,K-ATPase Endocytosis via Direct Phosphorylation of Protein Kinase C ${zeta}$

Galina A. Gusarova,¹^, Laura A. Dada,¹^, Aileen M. Kelly,¹ Chaya Brodie,² Lee A. Witters,³ Navdeep S. Chandel,¹ and Jacob I. Sznajder¹^*

Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois,¹ Department of Neurosurgery and Hermelin Brain Tumor Center, Henry Ford Health System, Detroit, Michigan,² Departments of Medicine and Biochemistry, Dartmouth Medical School, and Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire³

Received 13 January 2009/ Returned for modification 13 February 2009/ Accepted 10 April 2009

Hypoxia promotes Na,K-ATPase endocytosis via protein kinaseC ${zeta}$ (PKC ${zeta}$ )-mediated phosphorylation of the Na,K-ATPase ${alpha}$ subunit.Here, we report that hypoxia leads to the phosphorylation of5'-AMP-activated protein kinase (AMPK) at Thr172 in rat alveolarepithelial cells. The overexpression of a dominant-negativeAMPK ${alpha}$ subunit (AMPK-DN) construct prevented the hypoxia-inducedendocytosis of Na,K-ATPase. The overexpression of the reactiveoxygen species (ROS) scavenger catalase prevented hypoxia-inducedAMPK activation. Moreover, hypoxia failed to activate AMPK inmitochondrion-deficient ${rho}$ ⁰-A549 cells, suggesting that mitochondrialROS play an essential role in hypoxia-induced AMPK activation.Hypoxia-induced PKC ${zeta}$ translocation to the plasma membrane andphosphorylation at Thr410 were prevented by the pharmacologicalinhibition of AMPK or by the overexpression of the AMPK-DN construct.We found that AMPK ${alpha}$ phosphorylates PKC ${zeta}$ on residue Thr410 withinthe PKC ${zeta}$ activation loop. Importantly, the activation of AMPK ${alpha}$ was necessary for hypoxia-induced AMPK-PKC ${zeta}$ binding in alveolarepithelial cells. The overexpression of T410A mutant PKC ${zeta}$ preventedhypoxia-induced Na,K-ATPase endocytosis, confirming that PKC ${zeta}$ Thr410 phosphorylation is essential for this process. PKC ${zeta}$ activationby AMPK is isoform specific, as small interfering RNA targetingthe ${alpha}$ 1 but not the ${alpha}$ 2 catalytic subunit prevented PKC ${zeta}$ activation.Accordingly, we provide the first evidence that hypoxia-generatedmitochondrial ROS lead to the activation of the AMPK ${alpha}$ 1 isoform,which binds and directly phosphorylates PKC ${zeta}$ at Thr410, therebypromoting Na,K-ATPase endocytosis.

* Corresponding author. Mailing address: Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, 240 E. Huron, McGaw M-300, Chicago, IL 60611. Phone: (312) 908-7737. Fax: (312) 908-4650. E-mail: j-sznajder{at}northwestern.edu

Published ahead of print on 20 April 2009.

These authors contributed equally to this paper.

This article has been cited by other articles:

Sajan, M. P., Bandyopadhyay, G., Miura, A., Standaert, M. L., Nimal, S., Longnus, S. L., Van Obberghen, E., Hainault, I., Foufelle, F., Kahn, R., Braun, U., Leitges, M., Farese, R. V. (2010). AICAR and metformin, but not exercise, increase muscle glucose transport through AMPK-, ERK-, and PDK1-dependent activation of atypical PKC. Am. J. Physiol. Endocrinol. Metab. 298: E179-E192 [Abstract] [Full Text]