Fatty acid binding protein (Fabp) 5 interacts with the calnexin cytoplasmic domain at the endoplasmic reticulum.

Calnexin is a type 1 integral endoplasmic reticulum membrane molecular chaperone with an endoplasmic reticulum luminal chaperone domain and a highly conserved C-terminal domain oriented to the cytoplasm. Fabp5 is a cytoplasmic protein that binds long-chain fatty acids and other lipophilic ligands. Using a yeast two-hybrid screen, immunoprecipitation, microscale thermophoresis analysis and cellular fractionation, we discovered that Fabp5 interacts with the calnexin cytoplasmic C-tail domain at the endoplasmic reticulum. These observations identify Fabp5 as a previously unrecognized calnexin binding partner.