ARL13B regulates Sonic Hedgehog signaling from outside primary cilia
ARL13B is a regulatory GTPase highly enriched in cilia. Complete loss of Arl13b disrupts cilia architecture, protein trafficking and Sonic hedgehog signaling. To determine whether ARL13B is required within cilia, we knocked in a cilia-excluded variant of ARL13B (V358A) and showed it retains all known biochemical function. We found that ARL13BV358A protein was expressed but could not be detected in cilia, even when retrograde ciliary transport was blocked. We showed Arl13bV358A/V358A mice are viable and fertile with normal Shh signal transduction. However, in contrast to wild type cilia, Arl13bV358A/V358A cells displayed short cilia and lacked ciliary ARL3 and INPP5E. These data indicate that ARL13B's role within cilia can be uncoupled from its function outside of cilia. Furthermore, these data imply that the cilia defects upon complete absence of ARL13B do not underlie the alterations in Shh transduction, which is unexpected given the requirement of cilia for Shh transduction.
All data generated or analysed during this study are included in the manuscript and supporting files.
Article and author information
- Tamara Caspary
- Tamara Caspary
- Richard A Kahn
- Eduardo D Gigante
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Animal experimentation: All mice were cared for in accordance with NIH guidelines and Emory's Institutional Animal Care and Use Committee (IACUC) under protocols DAR-2003545-072919N and PROTO201700587.
- Jeremy F Reiter, University of California, San Francisco, United States
- Received: July 23, 2019
- Accepted: February 25, 2020
- Accepted Manuscript published: March 4, 2020 (version 1)
- Version of Record published: March 16, 2020 (version 2)
© 2020, Gigante et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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