The endocytosis of epidermal growth factor in A431 cells: A pH of microenvironment and the dynamics of receptor complex dissociation

Journal Article · Tue Mar 01 04:00:00 EST 1988 · Experimental Cell Research; (United States)

DOI:https://doi.org/10.1016/0014-4827(88)90266-2· OSTI ID:5322273

Sorkin, A D; Teslenko, L V; Nikolsky, N N ^[1]

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1. Institute of Cytology, Leningrad (USSR)

The endocytosis and intracellular fate of epidermal growth factor (EGF) were studied in A431 cells. After 15-20 min of internalization at 37{degree}C, rhodomaine-labeled ({sup 125}-I) EGF (EGR-Rh) accumulated into large juxtanuclear compartment consisting of closely related vesicles. This structure was shown to be localized in the para-Golgi region. Fluorescein-labeled transferrin (Tr-FITC) was observed in the same region when added to the cell simultaneously with EGF-Rh. Using microscopy spectrofluorometer, the authors determined that the Tr-FITC-containing para-Golgi structures have a pH of 6.1{plus minus}0.3 while lysosomes containing dextran-fluorescein have a pH of 5.0{plus minus}0.2. To study the dynamics of EGF-receptor dissociation during endocytosis a mild detergent treatment of living cells was used for extraction of an intracellular receptor-unbound EGF. These results suggest that EGF remains associated with receptors during endocytosis in A431 cells until it is transferred to lysosomes where the pH of the EGF microenvironment is dropped to 5. A prolonged presence of EGF-receptor complexes in the para-Golgi region might be of importance in mitotic signaling.

• OSTI ID: 5322273
• Journal Information: Experimental Cell Research; (United States), Journal Name: Experimental Cell Research; (United States) Vol. 175:1; ISSN ECREA; ISSN 0014-4827
• Country of Publication: United States
• Language: English

Related Subjects

550301* -- Cytology-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMAL TISSUES
AROMATICS
BETA DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BODY
CARBOXYLIC ACIDS
CELL CONSTITUENTS
COMPARTMENTS
DAYS LIVING RADIOISOTOPES
DYES
ELECTRON CAPTURE RADIOISOTOPES
EPIDERMIS
EPITHELIUM
FLUORESCEIN
GROWTH FACTORS
HYDROXY ACIDS
HYDROXY COMPOUNDS
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LYSOSOMES
MEMBRANE PROTEINS
MITOGENS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
PH VALUE
PHAGOCYTOSIS
PHENOLS
POLYPHENOLS
PROTEINS
RADIOISOTOPES
RADIORECEPTOR ASSAY
REACTION KINETICS
RECEPTORS
SKIN
TISSUES
TRACER TECHNIQUES