Caenorhabditis elegans screen reveals role of PAR-5 in RAB-11-recycling endosome positioning and apicobasal cell polarity.
Apically enriched Rab11-positive recycling endosomes (Rab11-REs) are important for establishing and maintaining epithelial polarity. Yet, little is known about the molecules controlling trafficking of Rab11-REs in an epithelium in vivo. Here, we report a genome-wide, image-based RNA interference screen for regulators of Rab11-RE positioning and transport of an apical membrane protein (PEPT-1) in C. elegans intestine. Among the 356 screen hits was the 14-3-3 and partitioning defective protein PAR-5, which we found to be specifically required for Rab11-RE positioning and apicobasal polarity maintenance. Depletion of PAR-5 induced abnormal clustering of Rab11-REs to ectopic sites at the basolateral cortex containing F-actin and other apical domain components. This phenotype required key regulators of F-actin dynamics and polarity, such as Rho GTPases (RHO-1 and the Rac1 orthologue CED-10) and apical PAR proteins. Our data suggest that PAR-5 acts as a regulatory hub for a polarity-maintaining network required for apicobasal asymmetry of F-actin and proper Rab11-RE positioning.
Max Planck Institute of Molecular Cell Biology and Genetics, MPI-CBG, Pfotenhauerstrasse 108, 01307 Dresden, Germany.
Julia Franziska
JF
Winter
Sebastian
S
Höpfner
Kerstin
K
Korn
Benjamin O
BO
Farnung
Charles R
CR
Bradshaw
Giovanni
G
Marsico
Michael
M
Volkmer
Bianca
B
Habermann
Marino
M
Zerial
D000199:Actins / Q000378:metabolism; D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D016764:Cell Polarity; D011992:Endosomes / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D005838:Genotype; D007413:Intestinal Mucosa / Q000378:metabolism*; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D008870:Microtubules / Q000378:metabolism; D000074011:Peptide Transporter 1; D010641:Phenotype; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D021381:Protein Transport; D034622:RNA Interference; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D027981:Symporters / Q000378:metabolism; D033921:Vesicular Transport Proteins / Q000235:genetics / Q000378:metabolism*; D020744:rac GTP-Binding Proteins / Q000378:metabolism; D020741:rho GTP-Binding Proteins / Q000378:metabolism
D000199:Actins; C407268:CED-10 protein, C elegans; D029742:Caenorhabditis elegans Proteins; D000074011:Peptide Transporter 1; D011993:Recombinant Fusion Proteins; D027981:Symporters; D033921:Vesicular Transport Proteins; C106207:par-5 protein, C elegans; C558453:rab-11.1 protein, C elegans; C409406:PAR-1 protein, C elegans; D017346:Protein Serine-Threonine Kinases; C560609:RHO-1 protein, C elegans; D020744:rac GTP-Binding Proteins; D020741:rho GTP-Binding Proteins