Biomaterial Database

Sequential interaction of the chaperones BiP and GRP94 with immunoglobulin chains in the endoplasmic reticulum. 1994

J Melnick, and J L Dul, and Y Argon

Department of Immunology, Duke University Medical Center, Durham, North Carolina 27710.

During their transit through the endoplasmic reticulum, newly synthesized light and heavy chains of immunoglobulins associate with two endoplasmic reticulum stress proteins. BiP/GRP78, a member of the HSP70 family, binds these polypeptides, presumably through promiscuously exposed hydrophobic sequences, soon after their translocation into the endoplasmic reticulum. GRP94, another endoplasmic reticulum stress protein homologous to HSP90, also associates with unassembled immunoglobulin chains, but its interaction is biochemically, kinetically and structurally distinct from BiP's. We report here that whereas BiP preferentially binds an early disulphide intermediate of light chain and dissociates within a few minutes, GRP94 exclusively binds fully oxidized molecules and dissociates with a half-time of 50 min. These results indicate that GRP94 is itself a chaperone which acts after BiP.

UI	MeSH Term	Description	Entries
D007147	Immunoglobulin Light Chains	Polypeptide chains, consisting of 211 to 217 amino acid residues and having a molecular weight of approximately 22 kDa. There are two major types of light chains, kappa and lambda. Two Ig light chains and two Ig heavy chains (IMMUNOGLOBULIN HEAVY CHAINS) make one immunoglobulin molecule.	Ig Light Chains,Immunoglobulins, Light-Chain,Immunoglobulin Light Chain,Immunoglobulin Light-Chain,Light-Chain Immunoglobulins,Chains, Ig Light,Chains, Immunoglobulin Light,Immunoglobulins, Light Chain,Light Chain Immunoglobulins,Light Chain, Immunoglobulin,Light Chains, Ig,Light Chains, Immunoglobulin,Light-Chain, Immunoglobulin
D008565	Membrane Proteins	Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.	Cell Membrane Protein,Cell Membrane Proteins,Cell Surface Protein,Cell Surface Proteins,Integral Membrane Proteins,Membrane-Associated Protein,Surface Protein,Surface Proteins,Integral Membrane Protein,Membrane Protein,Membrane-Associated Proteins,Membrane Associated Protein,Membrane Associated Proteins,Membrane Protein, Cell,Membrane Protein, Integral,Membrane Proteins, Integral,Protein, Cell Membrane,Protein, Cell Surface,Protein, Integral Membrane,Protein, Membrane,Protein, Membrane-Associated,Protein, Surface,Proteins, Cell Membrane,Proteins, Cell Surface,Proteins, Integral Membrane,Proteins, Membrane,Proteins, Membrane-Associated,Proteins, Surface,Surface Protein, Cell
D011485	Protein Binding	The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.	Plasma Protein Binding Capacity,Binding, Protein
D011506	Proteins	Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.	Gene Products, Protein,Gene Proteins,Protein,Protein Gene Products,Proteins, Gene
D002352	Carrier Proteins	Proteins that bind or transport specific substances in the blood, within the cell, or across cell membranes.	Binding Proteins,Carrier Protein,Transport Protein,Transport Proteins,Binding Protein,Protein, Carrier,Proteins, Carrier
D003517	Cyclopentanes	A group of alicyclic hydrocarbons with the general formula R-C5H9.	Cyclopentadiene,Cyclopentadienes,Cyclopentene,Cyclopentenes,Cyclopentane
D004721	Endoplasmic Reticulum	A system of cisternae in the CYTOPLASM of many cells. In places the endoplasmic reticulum is continuous with the plasma membrane (CELL MEMBRANE) or outer membrane of the nuclear envelope. If the outer surfaces of the endoplasmic reticulum membranes are coated with ribosomes, the endoplasmic reticulum is said to be rough-surfaced (ENDOPLASMIC RETICULUM, ROUGH); otherwise it is said to be smooth-surfaced (ENDOPLASMIC RETICULUM, SMOOTH). (King & Stansfield, A Dictionary of Genetics, 4th ed)	Ergastoplasm,Reticulum, Endoplasmic
D006360	Heat-Shock Proteins	Proteins which are synthesized in eukaryotic organisms and bacteria in response to hyperthermia and other environmental stresses. They increase thermal tolerance and perform functions essential to cell survival under these conditions.	Stress Protein,Stress Proteins,Heat-Shock Protein,Heat Shock Protein,Heat Shock Proteins,Protein, Stress
D000091342	Endoplasmic Reticulum Chaperone BiP	An ENDOPLASMIC RETICULUM specific chaperone of the HSP70 family. They are involved in folding and oligomerization of secreted and membrane proteins and ENDOPLASMIC RETICULUM STRESS related UNFOLDED PROTEIN RESPONSE.	Binding-immunoglobulin Protein Molecular Chaperone,Glucose Regulated Protein 78 kDa,Grp78,HSPA5 Protein,Heat-Shock Protein 5,Molecular Chaperone BiP,Molecular Chaperone GRP78,BiP, Molecular Chaperone,Binding immunoglobulin Protein Molecular Chaperone,GRP78, Molecular Chaperone,Heat Shock Protein 5,Protein, HSPA5
D014407	Tumor Cells, Cultured	Cells grown in vitro from neoplastic tissue. If they can be established as a TUMOR CELL LINE, they can be propagated in cell culture indefinitely.	Cultured Tumor Cells,Neoplastic Cells, Cultured,Cultured Neoplastic Cells,Cell, Cultured Neoplastic,Cell, Cultured Tumor,Cells, Cultured Neoplastic,Cells, Cultured Tumor,Cultured Neoplastic Cell,Cultured Tumor Cell,Neoplastic Cell, Cultured,Tumor Cell, Cultured