Long-term down-regulation of EGF-dependent tyrosine kinase activity in PC12 cells

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

OSTI ID:6798941

Lazarovici, P; Kuzuya, H; Dickens, G; Guroff, G

PC12 rat pheochromocytoma cells display cell surface receptors for both nerve growth factor (NGF) and epidermal growth factor (EGF), thus providing a model system with which to study their roles in the regulation of proliferation and differentiation. They have shown that treatment of the cells with NGF induces a progressive decrease (60-90%) in EGF receptors as monitored by (/sup 125/I)EGF binding and crosslinking. In the present report they determine EGF receptor levels in membranes from control and NGF-differentiated PC12 cells by monitoring EGF-receptor kinase activity. Measuring either the phosphorylation of a src-related synthetic peptide or the autophosphorylation of the receptor itself they found specific and maximal stimulation by 10 ng/ml EGF, but not by insulin, NGF, or cytochrome C, a complete dependency on Mn/sup 2 +/ ions, and higher specific activity in the presence of sodium vanadate. Alkaline treatment of the autophosphorylated receptor indicates that 75% of the /sup 32/P is associated with tyrosine residues. Membranes from NGF-differentiated cells show a decrease of 60-80% and 85-95% in the tyrosine kinase activity for exogenous substrate or receptor autophosphorylation, respectively. The possibility that the low levels of EGF-dependent tyrosine kinase activity in differentiated PC12 cells is an expression of a decrease in EGF receptor numbers and/or modulation of their catalytic activity by other kinases is under investigation.

• Research Organization: National Institute of Child Health and Human Development, Bethesda, MD
• OSTI ID: 6798941
• Report Number(s): CONF-8606151-
• Journal Information: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Vol. 45:6; ISSN FEPRA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
ANIMAL CELLS
ANIMAL TISSUES
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BODY
CARBOXYLIC ACIDS
CELL CONSTITUENTS
CELL MEMBRANES
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
ENZYME ACTIVITY
ENZYMES
EPIDERMIS
EPITHELIUM
HYDROXY ACIDS
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LIGHT NUCLEI
MAMMALS
MEMBRANE PROTEINS
MEMBRANES
NERVES
NERVOUS SYSTEM
NUCLEI
ODD-EVEN NUCLEI
ODD-ODD NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
PHOSPHORUS 32
PHOSPHORUS ISOTOPES
PHOSPHORUS-GROUP TRANSFERASES
PHOSPHOTRANSFERASES
PROTEINS
RADIOISOTOPES
RATS
REACTION KINETICS
RECEPTORS
RODENTS
SKIN
TISSUES
TRACER TECHNIQUES
TRANSFERASES
TUMOR CELLS
TYROSINE
VERTEBRATES