Journal Article

Arl13b regulates endocytic recycling traffic

Barral, Duarte C., Watts, Gerald F. M., Casalou, Cristina, Brenner, Michael B., Sandoval, José L., Hsu, Victor W., Ramalho, José S., Garg, Salil

2012

Overview

Intracellular recycling pathways play critical roles in internalizing membrane and fluid phase cargo and in balancing the inflow and outflow of membrane and cell surface molecules. To identify proteins involved in the regulation of endocytic recycling, we used an shRNA trafficking library and screened for changes in the surface expression of CD1a antigen-presenting molecules that follow an endocytic recycling route. We found that silencing of the ADP-ribosylation factor (Arf)-like small GTPase Arl13b led to a decrease in CD1a surface expression, diminished CD1a function, and delayed CD1a recycling, suggesting that Arl13b is involved in the regulation of endocytic recycling traffic. Arl13b appears to be required for the major route of endocytic trafficking, causing clustering of early endosomes and leading to the accumulation of endocytic cargo. Moreover, Arl13b colocalized with markers of the endocytic recycling pathway followed by CD1a, namely Arf6 and Rab22a. We also detected an interaction between Arl13b and the actin cytoskeleton. Arl13b was previously implicated in cilia formation and function. Our present results indicate a previously unidentified role for Arl13b in endocytic recycling traffic and suggest a link between Arl13b function and the actin cytoskeleton.

• Publisher: National Academy of Sciences,National Acad Sciences
• Subject: Actin Cytoskeleton - metabolism / Actins / Adenosine diphosphate / ADP-Ribosylation Factor 6 / ADP-Ribosylation Factors - chemistry / ADP-Ribosylation Factors - metabolism / Antigen presentation / Antigens, CD1 - metabolism / Biological Sciences / Cell Membrane - metabolism / Cell membranes / Cilia / Ciliary traffic / Cluster Analysis / Cytoskeleton / Endocytosis / Endosomes / Endosomes - metabolism / Freight / Gene expression / Gene Silencing / Green Fluorescent Proteins - metabolism / guanosinetriphosphatase / HeLa Cells / Humans / Immune response / Lipid antigens / Membranes / Microfilaments / Mutant Proteins - metabolism / Physiological regulation / Protein Binding / Protein Structure, Tertiary / Protein Transport / proteins / rab GTP-Binding Proteins - metabolism / Recycling / RNA-protein interactions / T lymphocytes / traffic / Transferrin - metabolism / Vesicle traffic