Lipoprotein lipase and leptin are accumulated in different secretory compartments in rat adipocytes.

Details

Serval ID
serval:BIB_51C4A6E63228
Type
Article: article from journal or magazin.
Collection
Publications
Title
Lipoprotein lipase and leptin are accumulated in different secretory compartments in rat adipocytes.
Journal
Journal of Biological Chemistry
Author(s)
Roh C., Roduit R., Thorens B., Fried S., Kandror K.V.
ISSN
0021-9258[print], 0021-9258[linking]
Publication state
Published
Issued date
2001
Volume
276
Number
38
Pages
35990-35994
Language
english
Notes
Publication types: In Vitro ; Journal Article ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, P.H.S.
Publication Status: ppublish
Abstract
Adipose cells produce and secrete several physiologically important proteins, such as lipoprotein lipase (LPL), leptin, adipsin, Acrp30, etc. However, secretory pathways in adipocytes have not been characterized, and vesicular carriers responsible for the accumulation and transport of secreted proteins have not been identified. We have compared the intracellular localization of two proteins secreted from adipose cells: leptin and LPL. Adipocytes accumulate large amounts of both proteins, suggesting that neither of them is targeted to the constitutive secretory pathway. By means of velocity centrifugation in sucrose gradients, equilibrium density centrifugation in iodixanol gradients, and immunofluorescence confocal microscopy, we determined that LPL and leptin were localized in different membrane structures. LPL was found mainly in the endoplasmic reticulum with a small pool being present in low density membrane vesicles that may represent a secretory compartment in adipose cells. Virtually all intracellular leptin was localized in these low density secretory vesicles. Insulin-sensitive Glut4 vesicles did not contain either LPL or leptin. Thus, secretion from adipose cells is controlled both at the exit from the endoplasmic reticulum as well as at the level of "downstream" secretory vesicles.
Keywords
Adipocytes/enzymology, Adipocytes/metabolism, Animals, Cell Compartmentation, Leptin/metabolism, Lipoprotein Lipase/metabolism, Male, Microscopy, Confocal, Microscopy, Fluorescence, Rats, Rats, Sprague-Dawley
Pubmed
Web of science
Open Access
Yes
Create date
24/01/2008 13:41
Last modification date
20/08/2019 14:07
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