Biomaterial Database

Invariant proteins associated with guinea-pig Ia antigens. 1983

H Quill, and B D Schwartz

Analysis of guinea-pig Ia immunoprecipitates by two-dimensional gel electrophoresis demonstrated the specific association of Ia molecules with several types of invariant proteins. These include a 33,000 mol. wt basic protein homologous to murine invariant chain (Ii), and a set of 34,000-36,000 mol. wt proteins more acidic than Ii (acidic invariant chain). Two 23,000-25,000 mol. wt non-polymorphic proteins with pIs of 6.0 and 6.5 were also observed in association with Ia, as was a basic protein of mol. wt 42,000. Pulse/chase studies using [35S]methionine demonstrated that Ii, but not acidic invariant chain, was associated with newly synthesized Ia molecules. The amount of 35S-Ii decreased greatly throughout the chase period. 35S-acidic invariant chain was clearly present in Ia precipitates by 30 min after Ia synthesis, but was not detected 4 hr after synthesis. Only acidic invariant chain was associated with mature Ia antigens bound by the lectin Ricinus communis I. Our results indicate that guinea-pig invariant proteins are differentially bound by Ia molecules during maturation of Ia alpha- and beta-chains, and suggest that acidic invariant chain could be a processed form of Ii.

UI	MeSH Term	Description	Entries
D008214	Lymphocytes	White blood cells formed in the body's lymphoid tissue. The nucleus is round or ovoid with coarse, irregularly clumped chromatin while the cytoplasm is typically pale blue with azurophilic (if any) granules. Most lymphocytes can be classified as either T or B (with subpopulations of each), or NATURAL KILLER CELLS.	Lymphoid Cells,Cell, Lymphoid,Cells, Lymphoid,Lymphocyte,Lymphoid Cell
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D010455	Peptides	Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are considered to be larger versions of peptides that can form into complex structures such as ENZYMES and RECEPTORS.	Peptide,Polypeptide,Polypeptides
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
D002478	Cells, Cultured	Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.	Cultured Cells,Cell, Cultured,Cultured Cell
D004591	Electrophoresis, Polyacrylamide Gel	Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.	Polyacrylamide Gel Electrophoresis,SDS-PAGE,Sodium Dodecyl Sulfate-PAGE,Gel Electrophoresis, Polyacrylamide,SDS PAGE,Sodium Dodecyl Sulfate PAGE,Sodium Dodecyl Sulfate-PAGEs
D006168	Guinea Pigs	A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.	Cavia,Cavia porcellus,Guinea Pig,Pig, Guinea,Pigs, Guinea
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D000949	Histocompatibility Antigens Class II	Large, transmembrane, non-covalently linked glycoproteins (alpha and beta). Both chains can be polymorphic although there is more structural variation in the beta chains. The class II antigens in humans are called HLA-D ANTIGENS and are coded by a gene on chromosome 6. In mice, two genes named IA and IE on chromosome 17 code for the H-2 antigens. The antigens are found on B-lymphocytes, macrophages, epidermal cells, and sperm and are thought to mediate the competence of and cellular cooperation in the immune response. The term IA antigens used to refer only to the proteins encoded by the IA genes in the mouse, but is now used as a generic term for any class II histocompatibility antigen.	Antigens, Immune Response,Class II Antigens,Class II Histocompatibility Antigen,Class II Major Histocompatibility Antigen,Ia Antigens,Ia-Like Antigen,Ia-Like Antigens,Immune Response Antigens,Immune-Associated Antigens,Immune-Response-Associated Antigens,MHC Class II Molecule,MHC II Peptide,Class II Antigen,Class II Histocompatibility Antigens,Class II MHC Proteins,Class II Major Histocompatibility Antigens,Class II Major Histocompatibility Molecules,I-A Antigen,I-A-Antigen,IA Antigen,MHC Class II Molecules,MHC II Peptides,MHC-II Molecules,Antigen, Class II,Antigen, I-A,Antigen, IA,Antigen, Ia-Like,Antigens, Class II,Antigens, Ia,Antigens, Ia-Like,Antigens, Immune-Associated,Antigens, Immune-Response-Associated,I A Antigen,II Peptide, MHC,Ia Like Antigen,Ia Like Antigens,Immune Associated Antigens,Immune Response Associated Antigens,MHC II Molecules,Molecules, MHC-II,Peptide, MHC II,Peptides, MHC II