title: Localization of sulfonylurea receptor subunits, SUR2A and SUR2B, in rat heart.
abstract: To understand the possible functions and subcellular localizations of sulfonylurea receptors (SURs) in cardiac muscle, polyclonal anti-SUR2A and anti-SUR2B antisera were raised. Immunoblots revealed both SUR2A and SUR2B expression in mitochondrial fractions of rat heart and other cellular fractions such as microsomes and cell membranes. Immunostaining detected ubiquitous expression of both SUR2A and SUR2B in rat heart in the atria, ventricles, interatrial and interventricular septa, and smooth muscles and endothelia of the coronary arteries. Electron microscopy revealed SUR2A immunoreactivity in the cell membrane, endoplasmic reticulum (ER), and mitochondria. SUR2B immunoreactivity was mainly localized in the mitochondria as well as in the ER and cell membrane. Thus, SUR2A and SUR2B are not only the regulatory subunits of sarcolemmal K(ATP) channels but may also function as regulatory subunits in mitochondrial K(ATP) channels and play important roles in cardioprotection.
authors: Department of Anatomy, Akita University School of Medicine, 1-1-1 Hondo, Akita 010-8543, Japan. mzhou@med.akita-u.ac.jp
authors: Ming
authors: M
authors: Zhou
authors: Hui-Jing
authors: HJ
authors: He
authors: Ryoji
authors: R
authors: Suzuki
authors: Ke-Xiang
authors: KX
authors: Liu
authors: Osamu
authors: O
authors: Tanaka
authors: Masaki
authors: M
authors: Sekiguchi
authors: Hideaki
authors: H
authors: Itoh
authors: Katsumasa
authors: K
authors: Kawahara
authors: Hiroshi
authors: H
authors: Abe
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000096:biosynthesis / Q000276:immunology / Q000378:metabolism*; D000818:Animals; D003331:Coronary Vessels / Q000378:metabolism; D007106:Immune Sera; D015151:Immunoblotting; D007150:Immunohistochemistry; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D032383:Myocytes, Cardiac / Q000378:metabolism / Q000648:ultrastructure; D009928:Organ Specificity; D015221:Potassium Channels / Q000096:biosynthesis / Q000276:immunology / Q000378:metabolism*; D024661:Potassium Channels, Inwardly Rectifying / Q000096:biosynthesis / Q000276:immunology / Q000378:metabolism*; D021122:Protein Subunits / Q000276:immunology / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D011955:Receptors, Drug / Q000096:biosynthesis / Q000276:immunology / Q000378:metabolism*; D064233:Sulfonylurea Receptors
chemical_list: D018528:ATP-Binding Cassette Transporters; D007106:Immune Sera; D015221:Potassium Channels; D024661:Potassium Channels, Inwardly Rectifying; D021122:Protein Subunits; D011955:Receptors, Drug; D064233:Sulfonylurea Receptors