Cystic fibrosis transmembrane conductance regulator in human and mouse red blood cell membranes and its interaction with ecto-apyrase

✍ Scribed by Kenneth M. Sterling Jr.; Sanjiv Shah; Ronald J. Kim; Nicholas I. F. Johnston; Anna Y. Salikhova; Edward H. Abraham

• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 201 KB
• Volume: 91
• Category: Article
• ISSN: 0730-2312
• DOI: 10.1002/jcb.20017

✦ Synopsis

Abstract

Elevated blood ATP and increased red blood cell (RBC) ATP transport is associated with cystic fibrosis (CF). In this report, we demonstrate the presence of the wild‐type and the ΔF508 mutant form of the CF transmembrane conductance regulator protein in RBC membranes and its putative interaction with ecto‐apyrase, an ATP hydrolyzing enzyme also present in the RBC membrane. RBC membranes of control and ΔF508 individuals and of wild‐type and CF transmembrane conductance regulator‐knockout mice were examined by immunoblot using several antibodies directed against different epitopes of this protein. These experiments indicated that human RBC membranes contain comparable amounts of the wild‐type CF transmembrane conductance regulator protein and the ΔF508 mutant form of the protein, respectively. CF transmembrane conductance regulator protein was also detected in wild‐type mouse RBC membranes but not in the gene knockout mouse RBC membranes. Antibodies directed against ecto‐apyrase co‐immunoprecipitated CF transmembrane conductance regulator protein of human RBC membranes indicating a physical interaction between these two membrane proteins consistent with ATP transport and extracellular hydrolysis. We conclude that RBCs are a significant repository of CF transmembrane conductance regulator protein and should provide a novel system for evaluating its expression and function. © 2004 Wiley‐Liss, Inc.