1. The peptide-binding activity of GRP94 is regulated by calcium
- Author
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Tali Gidalevitz, Olga Ostrovsky, Chhanda Biswas, Yair Argon, Catherine A. Makarewich, and Sherry Wanderling
- Subjects
chemistry.chemical_element ,Peptide binding ,Spodoptera ,Calcium ,Biochemistry ,Calcium in biology ,Cell Line ,Mice ,Animals ,Amino Acid Sequence ,Binding site ,Molecular Biology ,Peptide sequence ,Binding Sites ,Membrane Glycoproteins ,biology ,Chemistry ,Endoplasmic reticulum ,Calcium-Binding Proteins ,STIM1 ,Cell Biology ,Cell biology ,Chaperone (protein) ,biology.protein ,Peptides ,Research Article - Abstract
GRP94 (glucose-regulated protein of 94 kDa) is a major luminal constituent of the endoplasmic reticulum with known high capacity for calcium in vivo and a peptide-binding activity in vitro. In the present study, we show that Ca2+ regulates the ability of GRP94 to bind peptides. This effect is due to a Ca2+-binding site located in the charged linker domain of GRP94, which, when occupied, enhances the association of peptides with the peptide-binding site in the N-terminal domain of the protein. We further show that grp94−/− cells are hypersensitive to perturbation of intracellular calcium and thus GRP94 is important for cellular Ca2+ storage.
- Published
- 2007