Chloroquine allows the secretion of internalized SVI-epidermal growth factor from fibroblasts

Journal Article · Fri Nov 01 04:00:00 EST 1985 · J. Cell. Physiol.; (United States)

DOI:https://doi.org/10.1002/jcp.1041250207· OSTI ID:6331732

Wakshull, E; Cooper, J L; Wharton, W

Incubation of cells with labelled hormone in the presence of the lysosomotropic agent chloroquine produces an enhanced intracellular accumulation of hormone and receptor. Using a pulse-chase paradigm in which cell surface receptors were labelled with SVI-EGF at 4 degrees C, it was found that when 100 microM chloroquine was present in the 37 degrees C chase medium intact hormone was accumulated in the medium. Without chloroquine, low molecular weight (mw) degradation products were found in the medium. The processes of receptor-mediated endocytosis and subcellular distribution of SVI-EGF-receptor complexes were unchanged by chloroquine. The source of the intact hormone accumulating in the medium was therefore an intracellular compartment(s). The SVI-EGF released from the cells could rebind to surface receptors and be re-internalized; rebinding was inhibited by unlabelled EGF or Concanavalin A in the incubation medium. The concentration of unlabelled EGF required to inhibit rebinding was more than three orders of magnitude greater than the amount of SVI-EGF whose rebinding was inhibited. Thus, the SVI-EGF released from intracellular sites was rebound preferentially over exogenous EGF. The possible pathways for secretion of intact SVI-EGF and mechanisms of its preferential rebinding are discussed.

• Research Organization: Los Alamos National Lab., NM
• OSTI ID: 6331732
• Journal Information: J. Cell. Physiol.; (United States), Journal Name: J. Cell. Physiol.; (United States) Vol. 2; ISSN JCLLA
• Country of Publication: United States
• Language: English

Related Subjects

550201 -- Biochemistry-- Tracer Techniques
560301* -- Chemicals Metabolism & Toxicology-- Cells-- (-1987)
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AGGLUTININS
ANIMAL CELLS
ANIMALS
ANTIBODIES
AROMATICS
AZAARENES
AZINES
BETA DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL EFFECTS
BIOLOGICAL PATHWAYS
CELL CULTURES
CONCANAVALIN
CONNECTIVE TISSUE CELLS
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
FIBROBLASTS
HEMAGGLUTININS
HETEROCYCLIC COMPOUNDS
HORMONES
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
MAMMALS
MICE
MOLECULAR WEIGHT
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PYRIDINES
QUINOLINES
RADIOISOTOPES
REACTION KINETICS
RECEPTORS
RODENTS
SECRETION
SOMATIC CELLS
TRACER TECHNIQUES
VERTEBRATES