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-; TRN: 87-010315
• 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

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