Insulin-induced down-regulation of insulin receptors in 3T3-L1 adipocytes. Altered rate of receptor inactivation

G. V. Ronnett, V. P. Knutson, M. D. Lane

Research output: Contribution to journalArticle

Abstract

Fully differentiated 3T3-L1 adipocytes, maintained in the presence of insulin, exhibit up-regulation of insulin-binding capacity when insulin is removed from the culture medium. Both cell surface and total cellular insulin receptors increase by 1.8- to 2.0-fold during the 24-h period following the removal of insulin. When up-regulated 3T3-L1 cells are exposed to 10-8M insulin, down-regulation of insulin receptors occurs with a t 1/2 of 2-3 h. Down-regulation was complete after a 10-h exposure to insulin and resulted in a 50-60% decrease in levels of cell surface and total cellular insulin-binding capacities, respectively. Scatchard analysis revealed that these changes in insulin binding are due to an alteration of receptor number and not insulin-binding affinity. To clarify the mechanism(s) by which the regulation of insulin receptor level occurs, rates of receptor synthesis and degradation were determined by the heavy isotope density-shift method. No change in the rate of receptor synthesis occurred as a consequence of up-regulation or down-regulation. Up-regulation, however, caused an increase in receptor half-life from 8.1 h in the control cells to 14.8 h. Subsequent down-regulation brought about a return of receptor half-life to 6.9 h. These results indicate that insulin-dependent regulation of insulin receptor level in 3T3-L1 adipocytes involves a change in the rate of receptor degradation. Further studies indicated that regulation of insulin receptor level has physiological significance, since up-regulated cells exhibit an increased responsiveness of 2-deoxyglucose uptake to insulin compared to down-regulated cells.

Original languageEnglish (US)
Pages (from-to)4285-4291
Number of pages7
JournalJournal of Biological Chemistry
Volume257
Issue number8
StatePublished - 1982

Fingerprint

Insulin Receptor
Adipocytes
Down-Regulation
Insulin
Up-Regulation
Half-Life
3T3-L1 Cells
Degradation
Deoxyglucose
Isotopes
Culture Media

ASJC Scopus subject areas

  • Biochemistry

Cite this

Insulin-induced down-regulation of insulin receptors in 3T3-L1 adipocytes. Altered rate of receptor inactivation. / Ronnett, G. V.; Knutson, V. P.; Lane, M. D.

In: Journal of Biological Chemistry, Vol. 257, No. 8, 1982, p. 4285-4291.

Research output: Contribution to journalArticle

@article{594ea466094647ab8c7cb7bd43a6f924,
title = "Insulin-induced down-regulation of insulin receptors in 3T3-L1 adipocytes. Altered rate of receptor inactivation",
abstract = "Fully differentiated 3T3-L1 adipocytes, maintained in the presence of insulin, exhibit up-regulation of insulin-binding capacity when insulin is removed from the culture medium. Both cell surface and total cellular insulin receptors increase by 1.8- to 2.0-fold during the 24-h period following the removal of insulin. When up-regulated 3T3-L1 cells are exposed to 10-8M insulin, down-regulation of insulin receptors occurs with a t 1/2 of 2-3 h. Down-regulation was complete after a 10-h exposure to insulin and resulted in a 50-60{\%} decrease in levels of cell surface and total cellular insulin-binding capacities, respectively. Scatchard analysis revealed that these changes in insulin binding are due to an alteration of receptor number and not insulin-binding affinity. To clarify the mechanism(s) by which the regulation of insulin receptor level occurs, rates of receptor synthesis and degradation were determined by the heavy isotope density-shift method. No change in the rate of receptor synthesis occurred as a consequence of up-regulation or down-regulation. Up-regulation, however, caused an increase in receptor half-life from 8.1 h in the control cells to 14.8 h. Subsequent down-regulation brought about a return of receptor half-life to 6.9 h. These results indicate that insulin-dependent regulation of insulin receptor level in 3T3-L1 adipocytes involves a change in the rate of receptor degradation. Further studies indicated that regulation of insulin receptor level has physiological significance, since up-regulated cells exhibit an increased responsiveness of 2-deoxyglucose uptake to insulin compared to down-regulated cells.",
author = "Ronnett, {G. V.} and Knutson, {V. P.} and Lane, {M. D.}",
year = "1982",
language = "English (US)",
volume = "257",
pages = "4285--4291",
journal = "Journal of Biological Chemistry",
issn = "0021-9258",
publisher = "American Society for Biochemistry and Molecular Biology Inc.",
number = "8",

}

TY - JOUR

T1 - Insulin-induced down-regulation of insulin receptors in 3T3-L1 adipocytes. Altered rate of receptor inactivation

AU - Ronnett, G. V.

AU - Knutson, V. P.

AU - Lane, M. D.

PY - 1982

Y1 - 1982

N2 - Fully differentiated 3T3-L1 adipocytes, maintained in the presence of insulin, exhibit up-regulation of insulin-binding capacity when insulin is removed from the culture medium. Both cell surface and total cellular insulin receptors increase by 1.8- to 2.0-fold during the 24-h period following the removal of insulin. When up-regulated 3T3-L1 cells are exposed to 10-8M insulin, down-regulation of insulin receptors occurs with a t 1/2 of 2-3 h. Down-regulation was complete after a 10-h exposure to insulin and resulted in a 50-60% decrease in levels of cell surface and total cellular insulin-binding capacities, respectively. Scatchard analysis revealed that these changes in insulin binding are due to an alteration of receptor number and not insulin-binding affinity. To clarify the mechanism(s) by which the regulation of insulin receptor level occurs, rates of receptor synthesis and degradation were determined by the heavy isotope density-shift method. No change in the rate of receptor synthesis occurred as a consequence of up-regulation or down-regulation. Up-regulation, however, caused an increase in receptor half-life from 8.1 h in the control cells to 14.8 h. Subsequent down-regulation brought about a return of receptor half-life to 6.9 h. These results indicate that insulin-dependent regulation of insulin receptor level in 3T3-L1 adipocytes involves a change in the rate of receptor degradation. Further studies indicated that regulation of insulin receptor level has physiological significance, since up-regulated cells exhibit an increased responsiveness of 2-deoxyglucose uptake to insulin compared to down-regulated cells.

AB - Fully differentiated 3T3-L1 adipocytes, maintained in the presence of insulin, exhibit up-regulation of insulin-binding capacity when insulin is removed from the culture medium. Both cell surface and total cellular insulin receptors increase by 1.8- to 2.0-fold during the 24-h period following the removal of insulin. When up-regulated 3T3-L1 cells are exposed to 10-8M insulin, down-regulation of insulin receptors occurs with a t 1/2 of 2-3 h. Down-regulation was complete after a 10-h exposure to insulin and resulted in a 50-60% decrease in levels of cell surface and total cellular insulin-binding capacities, respectively. Scatchard analysis revealed that these changes in insulin binding are due to an alteration of receptor number and not insulin-binding affinity. To clarify the mechanism(s) by which the regulation of insulin receptor level occurs, rates of receptor synthesis and degradation were determined by the heavy isotope density-shift method. No change in the rate of receptor synthesis occurred as a consequence of up-regulation or down-regulation. Up-regulation, however, caused an increase in receptor half-life from 8.1 h in the control cells to 14.8 h. Subsequent down-regulation brought about a return of receptor half-life to 6.9 h. These results indicate that insulin-dependent regulation of insulin receptor level in 3T3-L1 adipocytes involves a change in the rate of receptor degradation. Further studies indicated that regulation of insulin receptor level has physiological significance, since up-regulated cells exhibit an increased responsiveness of 2-deoxyglucose uptake to insulin compared to down-regulated cells.

UR - http://www.scopus.com/inward/record.url?scp=0019943528&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0019943528&partnerID=8YFLogxK

M3 - Article

C2 - 7040381

AN - SCOPUS:0019943528

VL - 257

SP - 4285

EP - 4291

JO - Journal of Biological Chemistry

JF - Journal of Biological Chemistry

SN - 0021-9258

IS - 8

ER -