Unconventional Secretion of FABP4 by Endosomes and Secretory Lysosomes

Overview

Journal J Cell Biol

Specialty Cell Biology

Date 2017 Dec 8

PMID 29212659

Citations 45

Authors

Julien Villeneuve

Laia Bassaganyas

Sebastien Lepreux

Marioara Chiritoiu

Pierre Costet

Jean Ripoche

Vivek Malhotra

Randy Schekman

Affiliations

Soon will be listed here.

Abstract

An appreciation of the functional properties of the cytoplasmic fatty acid binding protein 4 (FABP4) has advanced with the recent demonstration that an extracellular form secreted by adipocytes regulates a wide range of physiological functions. Little, however, is known about the mechanisms that mediate the unconventional secretion of FABP4. Here, we demonstrate that FABP4 secretion is mediated by a membrane-bounded compartment, independent of the conventional endoplasmic reticulum-Golgi secretory pathway. We show that FABP4 secretion is also independent of GRASP proteins, autophagy, and multivesicular bodies but involves enclosure within endosomes and secretory lysosomes. We highlight the physiological significance of this pathway with the demonstration that an increase in plasma levels of FABP4 is inhibited by chloroquine treatment of mice. These findings chart the pathway of FABP4 secretion and provide a potential therapeutic means to control metabolic disorders associated with its dysregulated secretion.

Citing Articles

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