title: Stomatin interacts with GLUT1/SLC2A1, band 3/SLC4A1, and aquaporin-1 in human erythrocyte membrane domains.
abstract: The widely expressed, homo-oligomeric, lipid raft-associated, monotopic integral membrane protein stomatin and its homologues are known to interact with and modulate various ion channels and transporters. Stomatin is a major protein of the human erythrocyte membrane, where it associates with and modifies the glucose transporter GLUT1; however, previous attempts to purify hetero-oligomeric stomatin complexes for biochemical analysis have failed. Because lateral interactions of membrane proteins may be short-lived and unstable, we have used in situ chemical cross-linking of erythrocyte membranes to fix the stomatin complexes for subsequent purification by immunoaffinity chromatography. To further enrich stomatin, we prepared detergent-resistant membranes either before or after cross-linking. Mass spectrometry of the isolated, high molecular, cross-linked stomatin complexes revealed the major interaction partners as glucose transporter-1 (GLUT1), anion exchanger (band 3), and water channel (aquaporin-1). Moreover, ferroportin-1 (SLC40A1), urea transporter-1 (SLC14A1), nucleoside transporter (SLC29A1), the calcium-pump (Ca-ATPase-4), CD47, and flotillins were identified as stomatin-interacting proteins. These findings are in line with the hypothesis that stomatin plays a role as membrane-bound scaffolding protein modulating transport proteins.
authors.affiliation: Medical University of Vienna, Vienna, Austria.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Rungaldier
authors.forename: Walter
authors.initials: W
authors.lastname: Oberwagner
authors.forename: Ulrich
authors.initials: U
authors.lastname: Salzer
authors.forename: Edina
authors.initials: E
authors.lastname: Csaszar
authors.forename: Rainer
authors.initials: R
authors.lastname: Prohaska
mesh_terms: D001457:Anion Exchange Protein 1, Erythrocyte / Q000737:chemistry / Q000378:metabolism*; D051398:Aquaporin 1 / Q000378:metabolism*; D001703:Biophysics / Q000379:methods; D002846:Chromatography, Affinity / Q000379:methods; D003432:Cross-Linking Reagents / Q000494:pharmacology; D004910:Erythrocyte Membrane / Q000378:metabolism*; D004912:Erythrocytes / Q000166:cytology; D051272:Glucose Transporter Type 1 / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism*; D008954:Models, Biological; D010455:Peptides / Q000737:chemistry; D011485:Protein Binding; D025941:Protein Interaction Mapping / Q000379:methods; D017434:Protein Structure, Tertiary
chemical_list: D001457:Anion Exchange Protein 1, Erythrocyte; D003432:Cross-Linking Reagents; D051272:Glucose Transporter Type 1; D008565:Membrane Proteins; D010455:Peptides; C495677:SLC2A1 protein, human; C454201:SLC4A1 protein, human; C036860:STOM protein, human; D051398:Aquaporin 1