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Cardiac ATP‐sensitive K + channel associates with the glycolytic enzyme complex
Author(s) -
Hong Miyoun,
Kefaloyianni Eirini,
Bao Li,
Malester Brian,
Delaroche Diane,
Neubert Thomas A.,
Coetzee William A.
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fj.10-176669
Subject(s) - aldolase a , sulfonylurea receptor , glycolysis , pyruvate kinase , biochemistry , immunoprecipitation , biology , potassium channel , microbiology and biotechnology , enzyme , kir6.2 , chemistry , protein subunit , biophysics , gene
Being gated by high‐energy nucleotides, cardiac ATP‐sensitive potassium (K ATP ) channels are exquisitely sensitive to changes in cellular energy metabolism. An emerging view is that proteins associated with the K ATP channel provide an additional layer of regulation. Using putative sulfonylurea receptor (SUR) coiled‐coil domains as baits in a 2‐hybrid screen against a rat cardiac cDNA library, we identified glycolytic enzymes (GAPDH and aldolase A) as putative interacting proteins. Interaction between aldolase and SUR was confirmed using GST pulldown assays and coimmunoprecipitation assays. Mass spectrometry of proteins from K ATP channel immunoprecipitates of rat cardiac membranes identified glycolysis as the most enriched biological process. Coimmunoprecipitation assays confirmed interaction for several glycolytic enzymes throughout the glycolytic pathway. Immunocytochemistry colocalized many of these enzymes with K ATP channel subunits in rat cardiac myocytes. The catalytic activities of aldolase and pyruvate kinase functionally modulate K ATP channels in patch‐clamp experiments, whereas D‐glucose was without effect. Overall, our data demonstrate close physical association and functional interaction of the glycolytic process (particularly the distal ATP‐generating steps) with cardiac K ATP channels.—Hong, M., Kefaloyianni, E., Bao, L., Malester, B., Delaroche, D., Neubert, T. A., Coetzee, W. A. Cardiac ATP‐sensitive K + channel associates with the glycolytic enzyme complex. FASEB J. 25, 2456–2467 (2011). www.fasebj.org