Biomaterial Database

Insulin-like growth factor receptors and binding protein in rat neuroblastoma cells. 1989

M A Sturm, and C A Conover, and H Pham, and R G Rosenfeld

Department of Pediatrics, Stanford University Medical Center, California 94305.

B104, an established rat neuroblastoma cell line exhibiting specific neuronal qualities, was chosen as a model to study insulin-like growth factor (IGF) binding and action in the central nervous system. Specific binding of [125I]IGF-II to B104 membranes averaged 12.2 +/- 4.0% (mean +/- SD)/100 micrograms/ml protein compared with [125I]IGF-I binding of 10.1 +/- 2.9%. In competitive binding studies employing [125I]IGF-II as the radioligand, high affinity for IGF-II was demonstrated (50% displacement at 2.7 ng/ml), with none for IGF-I or insulin. Upon cross-linking [125I]IGF-I to membranes under reducing conditions, two prominent bands were observed, migrating with apparent mol wt (Mr) of 135,000 and 280,000. Both bands were inhibited by IGFs and insulin, but not by R-II-PABI, a polyclonal antibody to the type 2 receptor. These bands presumably represent the alpha-subunit and an incompletely reduced alpha-alpha-dimer of the type 1 IGF receptor. When cross-linking [125I]IGF-II to membranes under reducing conditions, the primary labeled bands migrated with apparent Mr of 260,000 and 280,000. These bands were inhibited by IGF-II and R-II-PABI, but not by insulin, and probably represent the monomeric type 2 receptor. In addition, we observed a minor band at apparent Mr 35,000, which was inhibited by IGF but not by insulin. By a modified cross-linking technique, we confirmed the existence of a small IGF-binding protein in the serum-free conditioned medium of B104 cultures, migrating as two bands with apparent Mr of 33,000-39,000. These proteins demonstrated high affinity for IGF-I and IGF-II, but none for insulin. In summary, this study demonstrates the presence in B104 rat neuroblastoma cells of 1) abundant classical type 1 and type 2 IGF receptors, and 2) a secreted and membrane-associated small IGF-binding protein.

UI	MeSH Term	Description	Entries
D007328	Insulin	A 51-amino acid pancreatic hormone that plays a major role in the regulation of glucose metabolism, directly by suppressing endogenous glucose production (GLYCOGENOLYSIS; GLUCONEOGENESIS) and indirectly by suppressing GLUCAGON secretion and LIPOLYSIS. Native insulin is a globular protein comprised of a zinc-coordinated hexamer. Each insulin monomer containing two chains, A (21 residues) and B (30 residues), linked by two disulfide bonds. Insulin is used as a drug to control insulin-dependent diabetes mellitus (DIABETES MELLITUS, TYPE 1).	Iletin,Insulin A Chain,Insulin B Chain,Insulin, Regular,Novolin,Sodium Insulin,Soluble Insulin,Chain, Insulin B,Insulin, Sodium,Insulin, Soluble,Regular Insulin
D007334	Insulin-Like Growth Factor I	A well-characterized basic peptide believed to be secreted by the liver and to circulate in the blood. It has growth-regulating, insulin-like, and mitogenic activities. This growth factor has a major, but not absolute, dependence on GROWTH HORMONE. It is believed to be mainly active in adults in contrast to INSULIN-LIKE GROWTH FACTOR II, which is a major fetal growth factor.	IGF-I,Somatomedin C,IGF-1,IGF-I-SmC,Insulin Like Growth Factor I,Insulin-Like Somatomedin Peptide I,Insulin Like Somatomedin Peptide I
D007335	Insulin-Like Growth Factor II	A well-characterized neutral peptide believed to be secreted by the LIVER and to circulate in the BLOOD. It has growth-regulating, insulin-like and mitogenic activities. The growth factor has a major, but not absolute, dependence on SOMATOTROPIN. It is believed to be a major fetal growth factor in contrast to INSULIN-LIKE GROWTH FACTOR I, which is a major growth factor in adults.	IGF-II,Multiplication-Stimulating Activity,Somatomedin MSA,IGF-2,Insulin Like Growth Factor II,Insulin-Like Somatomedin Peptide II,Multiplication-Stimulating Factor,Somatomedin A,Factor, Multiplication-Stimulating,Insulin Like Somatomedin Peptide II,Multiplication Stimulating Activity,Multiplication Stimulating Factor
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D009447	Neuroblastoma	A common neoplasm of early childhood arising from neural crest cells in the sympathetic nervous system, and characterized by diverse clinical behavior, ranging from spontaneous remission to rapid metastatic progression and death. This tumor is the most common intraabdominal malignancy of childhood, but it may also arise from thorax, neck, or rarely occur in the central nervous system. Histologic features include uniform round cells with hyperchromatic nuclei arranged in nests and separated by fibrovascular septa. Neuroblastomas may be associated with the opsoclonus-myoclonus syndrome. (From DeVita et al., Cancer: Principles and Practice of Oncology, 5th ed, pp2099-2101; Curr Opin Oncol 1998 Jan;10(1):43-51)	Neuroblastomas
D011972	Receptor, Insulin	A cell surface receptor for INSULIN. It comprises a tetramer of two alpha and two beta subunits which are derived from cleavage of a single precursor protein. The receptor contains an intrinsic TYROSINE KINASE domain that is located within the beta subunit. Activation of the receptor by INSULIN results in numerous metabolic changes including increased uptake of GLUCOSE into the liver, muscle, and ADIPOSE TISSUE.	Insulin Receptor,Insulin Receptor Protein-Tyrosine Kinase,Insulin Receptor alpha Subunit,Insulin Receptor beta Subunit,Insulin Receptor alpha Chain,Insulin Receptor beta Chain,Insulin-Dependent Tyrosine Protein Kinase,Receptors, Insulin,Insulin Receptor Protein Tyrosine Kinase,Insulin Receptors
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
D002462	Cell Membrane	The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.	Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
D003432	Cross-Linking Reagents	Reagents with two reactive groups, usually at opposite ends of the molecule, that are capable of reacting with and thereby forming bridges between side chains of amino acids in proteins; the locations of naturally reactive areas within proteins can thereby be identified; may also be used for other macromolecules, like glycoproteins, nucleic acids, or other.	Bifunctional Reagent,Bifunctional Reagents,Cross Linking Reagent,Crosslinking Reagent,Cross Linking Reagents,Crosslinking Reagents,Linking Reagent, Cross,Linking Reagents, Cross,Reagent, Bifunctional,Reagent, Cross Linking,Reagent, Crosslinking,Reagents, Bifunctional,Reagents, Cross Linking,Reagents, Cross-Linking,Reagents, Crosslinking
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