Glucocorticoid-regulated and constitutive trafficking of proteolytically processed cell surface-associated glycoproteins in wild type and variant rat hepatoma cells

Journal Article · Sun Oct 01 04:00:00 EDT 1989 · Molecular Endocrinology; (USA)

DOI:https://doi.org/10.1210/mend-3-10-1634· OSTI ID:7195070

Amacher, S L; Goodman, L J; Bravo, D A; Wong, K Y; Goldfine, I D; Hawley, D M; Firestone, G L ^[1]

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1. Univ. of California, Berkeley (USA)

Glucocorticoids regulate the trafficking of mouse mammary tumor virus (MMTV) glycoproteins to the cell surface in the rat hepatoma cell line M1.54, but not in the immunoselected sorting variant CR4. To compare the localization of MMTV glycoproteins to another proteolytically processed glycoprotein, both wild type M1.54 cells and variant CR4 cells were transfected with a human insulin receptor (hIR) expression vector, pRSVhIR. The production of cell surface hIR was monitored in dexamethasone-treated and -untreated wild type M1.54 and variant CR4 cells by indirect immunofluorescence, direct plasma membrane immunoprecipitation, and by (125I) insulin binding. In both wild type and variant rat hepatoma cells, hIR were localized at the cell surface in the presence or in the absence of 1 microM dexamethasone. In contrast, the glucocorticoid-regulated trafficking of cell surface MMTV glycoproteins occurred only in wild type M1.54 cells. We conclude that the hIR, which undergoes posttranslational processing reactions similar to MMTV glycoproteins, does not require glucocorticoids to be transported to the plasma membrane and is representative of a subset of cell surface glycoproteins whose trafficking is constitutive in rat hepatoma cells. Thus, MMTV glycoproteins and hIR provide specific cell surface markers to characterize the glucocorticoid-regulated and constitutive sorting pathways.

• OSTI ID: 7195070
• Journal Information: Molecular Endocrinology; (USA), Journal Name: Molecular Endocrinology; (USA) Vol. 3:10; ISSN 0888-8809; ISSN MOENE
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ADRENAL HORMONES
ANIMAL CELLS
ANIMALS
BETA DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL FUNCTIONS
BIOLOGICAL LOCALIZATION
BIOLOGICAL PATHWAYS
BODY
CELL CONSTITUENTS
CELL MEMBRANES
CORTICOSTEROIDS
DAYS LIVING RADIOISOTOPES
DEXAMETHASONE
DIGESTIVE SYSTEM
DISEASES
ELECTRON CAPTURE RADIOISOTOPES
EXPERIMENTAL NEOPLASMS
FLUORESCENCE
FUNCTIONS
GLANDS
GLUCOCORTICOIDS
GLYCOPROTEINS
HEPATOMAS
HORMONES
HYDROXY COMPOUNDS
INSULIN
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KETONES
KINETICS
LIVER
LUMINESCENCE
MAMMALS
MAMMARY GLANDS
MAN
MEMBRANE PROTEINS
MEMBRANE TRANSPORT
MEMBRANES
MICE
MICROORGANISMS
NEOPLASMS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
PARASITES
PEPTIDE HORMONES
PREGNANES
PRIMATES
PROTEINS
RADIOISOTOPES
RATS
REACTION KINETICS
RECEPTORS
RODENTS
STEROIDS
TRACER TECHNIQUES
TUMOR CELLS
VERTEBRATES
VIRUSES