In vitro mapping of calnexin interaction with ribosomes.
Calnexin is an endoplasmic reticulum (ER) resident type I integral membrane phosphoprotein. This protein is actively involved in the ER glycoprotein quality control through its luminal domain. In addition, although calnexin also interacts with membrane-bound ribosomes, the nature of this interaction remains poorly characterized. Herein, using in vitro approaches, we demonstrate that calnexin cytosolic domain directly interacts with, at least 5 ribosomal proteins. Furthermore, we characterize more specifically its interaction with the ribosomal protein L4 and that L4 binds to the 19 carboxy terminal amino acids of calnexin. We suggest that the direct interaction of calnexin with membrane-bound ribosomes may represent a regulatory mechanism for its lectin-like chaperone function.
Delom
Frédéric
F
Department of Surgery, McGill University, Montreal, PQ, Canada.
Chevet
Eric
E
D001665:Binding Sites; D037281:Calnexin / Q000737:chemistry*; D004926:Escherichia coli / Q000737:chemistry*; D011485:Protein Binding; D025941:Protein Interaction Mapping; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry; D012269:Ribosomal Proteins / Q000737:chemistry*; D012270:Ribosomes / Q000737:chemistry*
D011994:Recombinant Proteins; D012269:Ribosomal Proteins; C056368:ribosomal protein L4; D037281:Calnexin