Biomaterial Database

Modulation of EGF-receptors by phorbol ester in small intestinal crypt cells. 1990

B S Baliga, and S M Borowitz, and J A Barnard

Department of Pediatrics, University of South Alabama College of Medicine, Mobile 36617.

We have previously shown that EGF promotes growth and proliferation of enterocytes isolated from the crypts of the rat small intestine (IEC-6). In the present studies we have measured the affinity of EGF for its receptor, and estimated the number of surface EGF receptors on IEC-6 cells. Scatchard analysis indicates IEC-6 cells display 45,000 EGF receptors per cell with a dissociation constant of 41 pM. Treatment with phorbol-12-myristate-13-acetate (PMA) results in a dose-dependent inhibition of cell growth which is paralleled by reduced binding of 125I-EGF. Incubation of IEC-6 cells with 10 nM PMA results in a 70 percent decrease in the number of EGF receptors without a significant change of receptor affinity (kd 68 pM vs 41 pM). PMA treatment is also associated with a significant increase of protein kinase-C activity in IEC-6 cells. The reciprocal relationship between protein kinase-C activation and EGF receptors suggests in this cell line of crypt enterocytes, protein kinase-C may inhibit cellular proliferation by modulating EGF receptors.

UI	MeSH Term	Description	Entries
D007421	Intestine, Small	The portion of the GASTROINTESTINAL TRACT between the PYLORUS of the STOMACH and the ILEOCECAL VALVE of the LARGE INTESTINE. It is divisible into three portions: the DUODENUM, the JEJUNUM, and the ILEUM.	Small Intestine,Intestines, Small,Small Intestines
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D011493	Protein Kinase C	An serine-threonine protein kinase that requires the presence of physiological concentrations of CALCIUM and membrane PHOSPHOLIPIDS. The additional presence of DIACYLGLYCEROLS markedly increases its sensitivity to both calcium and phospholipids. The sensitivity of the enzyme can also be increased by PHORBOL ESTERS and it is believed that protein kinase C is the receptor protein of tumor-promoting phorbol esters.	Calcium Phospholipid-Dependent Protein Kinase,Calcium-Activated Phospholipid-Dependent Kinase,PKC Serine-Threonine Kinase,Phospholipid-Sensitive Calcium-Dependent Protein Kinase,Protein Kinase M,Calcium Activated Phospholipid Dependent Kinase,Calcium Phospholipid Dependent Protein Kinase,PKC Serine Threonine Kinase,Phospholipid Sensitive Calcium Dependent Protein Kinase,Phospholipid-Dependent Kinase, Calcium-Activated,Serine-Threonine Kinase, PKC
D002455	Cell Division	The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.	M Phase,Cell Division Phase,Cell Divisions,Division Phase, Cell,Division, Cell,Divisions, Cell,M Phases,Phase, Cell Division,Phase, M,Phases, M
D002460	Cell Line	Established cell cultures that have the potential to propagate indefinitely.	Cell Lines,Line, Cell,Lines, Cell
D004305	Dose-Response Relationship, Drug	The relationship between the dose of an administered drug and the response of the organism to the drug.	Dose Response Relationship, Drug,Dose-Response Relationships, Drug,Drug Dose-Response Relationship,Drug Dose-Response Relationships,Relationship, Drug Dose-Response,Relationships, Drug Dose-Response
D004789	Enzyme Activation	Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.	Activation, Enzyme,Activations, Enzyme,Enzyme Activations
D004815	Epidermal Growth Factor	A 6-kDa polypeptide growth factor initially discovered in mouse submaxillary glands. Human epidermal growth factor was originally isolated from urine based on its ability to inhibit gastric secretion and called urogastrone. Epidermal growth factor exerts a wide variety of biological effects including the promotion of proliferation and differentiation of mesenchymal and EPITHELIAL CELLS. It is synthesized as a transmembrane protein which can be cleaved to release a soluble active form.	EGF,Epidermal Growth Factor-Urogastrone,Urogastrone,Human Urinary Gastric Inhibitor,beta-Urogastrone,Growth Factor, Epidermal,Growth Factor-Urogastrone, Epidermal,beta Urogastrone
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
D001667	Binding, Competitive	The interaction of two or more substrates or ligands with the same binding site. The displacement of one by the other is used in quantitative and selective affinity measurements.	Competitive Binding