title: Fibulin-1C, C1 Esterase Inhibitor and Glucose Regulated Protein 75 Interact with the CREC Proteins, Calumenin and Reticulocalbin.
abstract: Affinity purification, immunoprecipitation, gel electrophoresis and mass spectrometry were used to identify fibulin-1C, C1 esterase inhibitor and glucose regulated protein 75, grp75, as binding partners of the CREC proteins, calumenin and reticulocalbin. Surface plasmon resonance was used to verify the interaction of all three proteins with each of the CREC proteins. Fibulin-1C interacts with calumenin and reticulocalbin with an estimated dissociation constant around 50-60 nM. The interaction, at least for reticulocalbin, was not dependent upon the presence of Ca2+. C1 esterase inhibitor interacted with both proteins with an estimated dissociation constant at 1 μM for reticulocalbin and 150 nM for calumenin. The interaction, at least for calumenin, was dependent upon the presence of Ca2+ with strong interaction at 3.5 mM while no detectable interaction could be found at 0.1 mM. Grp75 binds with an affinity of approximately 3-7 nM with reticulocalbin as well as with calumenin. These interactions suggest functional participation of the CREC proteins in chaperone activity, cell proliferation and transformation, cellular aging, haemostasis and thrombosis as well as modulation of the complement system in fighting bacterial infection.
authors.affiliation: Department of Biomedicine, Ole Worms Allé 3, Building 1182, Aarhus University, DK-8000 Aarhus C, Denmark.
authors.forename: Gry Aune Westergaard
authors.initials: GA
authors.lastname: Hansen
authors.affiliation: Department of Biomedicine, Ole Worms Allé 3, Building 1182, Aarhus University, DK-8000 Aarhus C, Denmark.
authors.forename: Maja
authors.initials: M
authors.lastname: Ludvigsen
authors.affiliation: Department of Biomedicine, Ole Worms Allé 3, Building 1182, Aarhus University, DK-8000 Aarhus C, Denmark.
authors.forename: Christian
authors.initials: C
authors.lastname: Jacobsen
authors.affiliation: Department of Clinical Biochemistry and Pharmacology, Center for Individualized Medicine in Arterial Diseases (CIMA), Odense University Hospital, Sdr. Boulevard 29, DK-5000 Odense C, Denmark.
authors.forename: Claudia
authors.initials: C
authors.lastname: Cangemi
authors.forename: Lars Melholt
authors.initials: LM
authors.lastname: Rasmussen
authors.affiliation: Department of Ophthalmology, Aalborg University Hospital, Hobrovej 18-22, 9100 Aalborg, Denmark.
authors.forename: Henrik
authors.initials: H
authors.lastname: Vorum
authors.affiliation: Department of Biomedicine, Ole Worms Allé 3, Building 1182, Aarhus University, DK-8000 Aarhus C, Denmark.
authors.forename: Bent
authors.initials: B
authors.lastname: Honoré
mesh_terms: D000595:Amino Acid Sequence; D001158:Arteries / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D002460:Cell Line; D002846:Chromatography, Affinity; D050718:Complement C1 Inhibitor Protein / Q000378:metabolism*; D005260:Female; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism*; D006801:Humans; D007106:Immune Sera / Q000378:metabolism; D007150:Immunohistochemistry; D047468:Immunoprecipitation; D013058:Mass Spectrometry; D008565:Membrane Proteins / Q000378:metabolism*; D018613:Microscopy, Confocal; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000378:metabolism; D010920:Placenta / Q000378:metabolism; D011247:Pregnancy; D011485:Protein Binding; D015203:Reproducibility of Results; D020349:Surface Plasmon Resonance
chemical_list: D002135:Calcium-Binding Proteins; D050718:Complement C1 Inhibitor Protein; D018840:HSP70 Heat-Shock Proteins; D007106:Immune Sera; D008565:Membrane Proteins; D010455:Peptides; C060820:fibulin; C018551:glucose-regulated proteins; C078865:reticulocalbin