Please use this identifier to cite or link to this item: http://ahro.austin.org.au/austinjspui/handle/1/10329
Title: Regulation of the renal-specific Na+-K+-2Cl- co-transporter NKCC2 by AMP-activated protein kinase (AMPK).
Authors: Fraser, Scott A;Gimenez, Ignacio;Cook, Natasha;Jennings, Ian;Katerelos, Marina;Katsis, Frosa;Levidiotis, Vicki;Kemp, Bruce E;Power, David Anthony
Affiliation: sfraser@burnet.edu.au
The Burnet Research Institute, Austin Health, Studley Road, Heidelberg, Victoria 3084, Australia
Issue Date: 1-Jul-2007
Citation: The Biochemical Journal; 405(1): 85-93
Abstract: The renal-specific NKCC2 (Na+-K+-2Cl- co-transporter 2) is regulated by changes in phosphorylation state, however, the phosphorylation sites and kinases responsible have not been fully elucidated. In the present study, we demonstrate that the metabolic sensing kinase AMPK (AMP-activated protein kinase) phosphorylates NKCC2 on Ser126 in vitro. Co-precipitation experiments indicated that there is a physical association between AMPK and the N-terminal cytoplasmic domain of NKCC2. Activation of AMPK in the MMDD1 (mouse macula densa-derived 1) cell line resulted in an increase in Ser126 phosphorylation in situ, suggesting that AMPK may phosphorylate NKCC2 in vivo. The functional significance of Ser126 phosphorylation was examined by mutating the serine residue to an alanine residue resulting in a marked reduction in co-transporter activity when exogenously expressed in Xenopus laevis oocytes under isotonic conditions. Under hypertonic conditions no significant change of activity was observed. Therefore the present study identifies a novel phosphorylation site that maintains NKCC2-mediated transport under isotonic or basal conditions. Moreover, the metabolic-sensing kinase, AMPK, is able to phosphorylate this site, potentially linking the cellular energy state with changes in co-transporter activity.
Internal ID Number: 17341212
URI: http://ahro.austin.org.au/austinjspui/handle/1/10329
DOI: 10.1042/BJ20061850
URL: http://www.ncbi.nlm.nih.gov/pubmed/17341212
Type: Journal Article
Subjects: AMP-Activated Protein Kinases
Amino Acid Sequence
Animals
Antibodies, Phospho-Specific.metabolism
Cell Line
Enzyme Activation
Humans
Kidney.metabolism
Mice
Molecular Sequence Data
Multienzyme Complexes.genetics.metabolism
Oocytes.cytology.physiology
Phosphorylation
Protein-Serine-Threonine Kinases.genetics.metabolism
Recombinant Fusion Proteins.genetics.metabolism
Reproducibility of Results
Rubidium.metabolism
Sequence Alignment
Serine.metabolism
Sodium-Potassium-Chloride Symporters.genetics.metabolism
Solute Carrier Family 12, Member 1
Xenopus laevis
Appears in Collections:Journal articles

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