Epidermal growth factor (EGF)-receptor is phosphorylated at threonine-654 in A431 cells following EGF addition

Conference · Thu May 01 00:00:00 EDT 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:6754535

Whiteley, B; Glaser, L

It has been shown that activation of protein kinase C by tumor-promoting phorbol diesters causes phorphorylation of the EGF-receptor at threonine-654 and is believed to thereby regulate the EGF receptor tyrosine kinase and EGF binding activity. In their present studies, /sup 32/P-labeled A431 cells were treated with and without 10 nM phorbol 12-myristate 13-acetate (PMA), or with 200 ng/ml EGF. Analysis of /sup 32/P-labeled EGF receptor tryptic phosphopeptides by reverse-phase HPLC confirmed the known effects of PMA and revealed that EGF caused phosphorylation at threonine-654 as well as various tyrosine residues. This effect occurred as early as 1 minute after EGF addition and was maximal after 5 minutes. The magnitude of the response appears to be 50% of a 15 minute treatment with 10 nM PMA. Direct measurement of diacylglycerol using an E. coli diacylglycerol kinase confirmed that EGF-stimulated phosphoinositide turnover could cause very rapid activation of protein kinase C. These results imply that protein kinase C is playing a role in negative modulation of EGF-receptor activity following EGF addition to A431 cells.

• Research Organization: Washington Univ. School of Medicine, St. Louis, MO
• OSTI ID: 6754535
• Report Number(s): CONF-8606151-; TRN: 87-011177
• Journal Information: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 45:6; Conference: 76. annual meeting of the Federation of American Society for Experimental Biology, Washington, DC, USA, 8 Jun 1986
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
59 BASIC BIOLOGICAL SCIENCES
PHORBOL ESTERS
BIOLOGICAL EFFECTS
PHOSPHOTRANSFERASES
ENZYME ACTIVITY
PROTEINS
RECEPTORS
PHOSPHORYLATION
LIQUID COLUMN CHROMATOGRAPHY
PHOSPHORUS 32
TRACER TECHNIQUES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARCINOGENS
CHEMICAL REACTIONS
CHROMATOGRAPHY
DAYS LIVING RADIOISOTOPES
ENZYMES
ESTERS
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
MEMBRANE PROTEINS
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
PHOSPHORUS ISOTOPES
PHOSPHORUS-GROUP TRANSFERASES
RADIOISOTOPES
SEPARATION PROCESSES
TRANSFERASES
560300* - Chemicals Metabolism & Toxicology
550201 - Biochemistry- Tracer Techniques