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This article is part of the supplement: Proceedings of the First International Cilia in Development and Disease Scientific Conference (2012)

Open Access Open Badges Poster presentation

The GMAP210 homologue SQL 1 modulates intraflagellar transport in C. elegans

S Rademakers1*, J Broekhuis1, M Dekkers2, J Burghoorn1 and G Jansen1

Author Affiliations

1 Erasmus Medical Center Rotterdam, the Netherlands

2 Biozentrum, University Basel, Switzerland

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Cilia 2012, 1(Suppl 1):P40  doi:10.1186/2046-2530-1-S1-P40

The electronic version of this article is the complete one and can be found online at:

Published:16 November 2012

© 2012 Rademakers et al; licensee BioMed Central Ltd.

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Poster presentation

The development and function of cilia require a specialised transport process, called Intraflagellar Transport (IFT). In amphid cilia of C. elegans this process uses two kinesins, kinesin II and OSM-3, which are loaded with complex A and B particle proteins and cargo molecules. We have previously shown that expression of a dominant active G-protein (GPA-3QL) in amphid channel neurons affects the coordination of OSM-3 and kinesin-II and results in shorter cilia. We performed a genetic screen to identify mutants that suppress the gpa-3QL cilia length defect and identified sql-1 (supressor of gpa-3QL), which encodes the homologue of the mammalian Golgi protein GMAP210. GMAP210 has been shown to play a role in vesicular transport from the Golgi apparatus to the cilium. SQL-1 is ubiquitously expressed in C. elegans and localizes to the Golgi. sql-1 loss of function (lf) mutants show wildtype length cilia, while animals overexpressing SQL-1 have longer cilia. Speed measurements in sql-1(lf) animals showed that OSM-3 moves faster and kinesin II moves slower, suggesting that the two kinesins are partially uncoupled. Complex A and B proteins move at the same speed as OSM-3, suggesting that IFT is predominantly mediated by OSM-3 kinesin. Interestingly, in the gpa-3QL; sql-1(lf) double mutants the speed of OSM-3 is decreased. We hypothesize that SQL-1 plays a role in routing or post translational modifications of proteins that are required in the cilium for proper IFT.