EGF-induced stimualtion of EGF-receptor synthesis in human cytotrophoblasts and A431 cells

Conference · Fri May 01 04:00:00 EDT 1987 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:6286297

DePalo, L; Basu, A; Das, M

EGF-receptor is a transmembrane glycoprotein whose intracellular degradation is known to be enhanced by EGF. The authors tested whether the receptor is replenished during this process by an enhanced rate of synthesis. Human A431 epidermoid carcinoma cells, and primary cultures of human placental cytotrophoblasts were used in these studies. Cells were labeled with TVS-methionine, and EGF-receptor biosynthesis was quantitated by immunoprecipitation using a monoclonal anti-EGF-receptor antibody. EGF stimulated receptor biosynthesis at concentrations of 0.1-1 nM. The effect was seen within 2 h of EGF addition. The maximal stimulatory effect was modest in A431 (approx. 2-fold), but marked in the cytotrophoblasts (>5-fold). At EGF concentrations higher than 3 nM, the stimulatory effect was abolished. In contrast, the effect of EGF on receptor degradation is negligible at low subnanomolar concentrations, and is pronounced only at saturating concentrations. These results show that occupation of the cell surface EGF-receptor by its ligand can lead to production of more receptor protein, thus counterbalancing the negative effect on receptor degradation. At low subnanomolar (mitogenic) concentrations of EGF the stimulator effect on receptor synthesis is likely to predominate over the effect on receptor degradation.

• Research Organization: Univ. of Pennsylvania, Philadelphia
• OSTI ID: 6286297
• Report Number(s): CONF-870644-
• Conference Information: Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Journal Volume: 46:6
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
ANIMAL CELLS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOSYNTHESIS
CARBOXYLIC ACIDS
DAYS LIVING RADIOISOTOPES
DRUGS
EVEN-ODD NUCLEI
HORMONES
ISOTOPE APPLICATIONS
ISOTOPES
LIGANDS
LIGHT NUCLEI
LIPOTROPIC FACTORS
MAMMALS
MAN
METHIONINE
NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PEPTIDE HORMONES
PRIMATES
RADIOISOTOPES
RECEPTORS
SULFUR 35
SULFUR ISOTOPES
SYNTHESIS
TRACER TECHNIQUES
TUMOR CELLS
VERTEBRATES