PT  - JOURNAL ARTICLE
AU  - SM Niedziółka
AU  - S Datta
AU  - T Uśpieński
AU  - B Baran
AU  - EW Humke
AU  - R Rohatgi
AU  - P Niewiadomski
TI  - The exocyst complex and intracellular vesicles mediate soluble protein trafficking to the primary cilium
AID  - 10.1101/2021.09.27.461918
DP  - 2021 Jan 01
TA  - bioRxiv
PG  - 2021.09.27.461918
4099  - http://biorxiv.org/content/early/2021/09/28/2021.09.27.461918.short
4100  - http://biorxiv.org/content/early/2021/09/28/2021.09.27.461918.full
AB  - Efficient transport of proteins into the primary cilium is a crucial step for many signaling pathways. Dysfunction of this process can lead to the disruption of signaling cascades or cilium assembly, resulting in developmental disorders and cancer. Previous studies on ciliary trafficking were mostly focused on the membrane-embedded receptors. In contrast, how soluble proteins are delivered into the cilium is poorly understood. In our work, we identify the exocyst complex as a key player in the ciliary trafficking of soluble Gli transcription factors. Considering that the exocyst mediates intracellular vesicle transport, we demonstrate that soluble proteins, including Gli2/3 and Lkb1, can use the endosome recycling machinery for their delivery to the primary cilium. Finally, we identify GTPases: Rab14, Rab18, Rab23, and Arf4 involved in vesicle-mediated Gli protein ciliary trafficking. Our data pave the way for a better understanding of ciliary transport and uncover novel transport mechanisms inside the cell.Competing Interest StatementThe authors have declared no competing interest.