@article{164f882db8a84ec398aa64130188955a,
title = "Rab22a regulates the establishment of epithelial polarity",
abstract = "Membrane trafficking establishes and maintains epithelial polarity. Rab22a has a polarized distribution in activated T-cells, but its role in epithelial polarity has not been investigated. We showed previously that Rab14 acts upstream of Arf6 to establish the apical membrane initiation site (AMIS), but its interaction with Rab22a is unknown. Here we show that Rab14 and Rab22a colocalize in endosomes of both unpolarized and polarized MDCK cells and Rab22a localizes to the cell:cell interface of polarizing cell pairs. Knockdown of Rab22a results in a multi-lumen phenotype in three-dimensional culture. Further, overexpression of Rab22a in Rab14 knockdown cells rescues the multi-lumen phenotype observed with Rab14 knockdown, suggesting that Rab22a is downstream of Rab14. Because of the relationship between Rab14 and Arf6, we investigated the effect of Rab22a knockdown on Arf6. We find that Rab22a knockdown results in decreased active Arf6 and that Rab22a co-immunoprecipitates with the Arf6 GEF EFA6. In addition, EFA6 is retained in intracellular puncta in Rab22a KD cells. These results suggest that Rab22a acts downstream of Rab14 to traffic EFA6 to the AMIS to regulate Arf6 in the establishment of polarity.",
keywords = "Arf6, Efa6, Rab14, Rab22a, apical membrane initiation site, membrane trafficking, multi-lumen, polarity",
author = "Blum, {Isabella R.} and Caroline Behling-Hess and Marco Padilla-Rodriguez and Samina Momtaz and Christopher Cox and Wilson, {Jean M.}",
note = "Funding Information: We would like to thank Julie Donaldson (National Institutes of Health) for her kind gift of Rab22a-WT-GFP, and Rab22a-Q64L-GFP, and James Casanova (University of Virginia) for providing EFA6-FLAG and ARNO-Myc plasmids and helpful discussions. We thank Ruifeng Lu for help with three-dimensional cyst culture and the Wilson lab for helpful discussions. This work was funded by the National Institutes of Health RO1 DK109701 (J.M.W.), The University of Arizona Honors College Spirit of Inquiry fellowship (I.R.B.), a Science Education Award from the Howard Hughes Medical Institute to Macalester College (C.B.H.), and The University of Arizona Cancer Center (National Cancer Institute Cancer Center Support Grant P30 CA023074). Funding Information: This work was supported by the Howard Hughes Medical Institute [Science Education Award Macalester College]; National Cancer Institute [P30 CA023074]; National Institute of Diabetes and Digestive and Kidney Diseases [RO1 DK109701]; University of Arizona [Honors College]. We would like to thank Julie Donaldson (National Institutes of Health) for her kind gift of Rab22a-WT-GFP, and Rab22a-Q64L-GFP, and James Casanova (University of Virginia) for providing EFA6-FLAG and ARNO-Myc plasmids and helpful discussions. We thank Ruifeng Lu for help with three-dimensional cyst culture and the Wilson lab for helpful discussions. This work was funded by the National Institutes of Health RO1 DK109701 (J.M.W.), The University of Arizona Honors College Spirit of Inquiry fellowship (I.R.B.), a Science Education Award from the Howard Hughes Medical Institute to Macalester College (C.B.H.), and The University of Arizona Cancer Center (National Cancer Institute Cancer Center Support Grant P30 CA023074). Publisher Copyright: {\textcopyright} 2020 Informa UK Limited, trading as Taylor & Francis Group.",
year = "2021",
doi = "10.1080/21541248.2020.1754104",
language = "English (US)",
volume = "12",
pages = "282--293",
journal = "Small GTPases",
issn = "2154-1248",
publisher = "Landes Bioscience",
number = "4",
}