Abstract: PO1226
Rab GTPase Regulation in Ciliogenesis and Polycystic Kidney Disease
Session Information
- Cystic Kidney Disease - I
November 04, 2021 | Location: On-Demand, Virtual Only
Abstract Time: 10:00 AM - 12:00 PM
Category: Genetic Diseases of the Kidneys
- 1001 Genetic Diseases of the Kidneys: Cystic
Authors
- Mcconnachie, Dominique J., The University of Queensland Institute for Molecular Bioscience, Saint Lucia, Queensland, Australia
- Mallett, Andrew John, Townsville Hospital and Health Service, Townsville, Queensland, Australia
- Stow, Jennifer L., The University of Queensland Institute for Molecular Bioscience, Saint Lucia, Queensland, Australia
Group or Team Name
- Professor Jennifer Stow, Protein trafficking and inflammation group
Background
Primary cilia are sensory organelles with widespread roles in development and epithelial function. Mutations resulting in dysmorphic cilia and ciliary dysfunction are associated with renal ciliopathies such as polycystic kidney disease (PKD), yet primary cilia remain enigmatic in terms of their molecular and functional characterisation. Rab GTPases are master regulators of vesicular trafficking that have been shown to regulate ciliogenesis and cilium composition, with downstream effects on ciliary function and signalling. Rabs are therefore poised to vary or modify primary ciliary function, by working in conjunction with key cilia proteins, including those mutated in PKD and other ciliopathies. Hence, we are examining novel roles for Rab GTPases in cilia formation and function and Rab13 has been the focus of recent studies.
Methods
Expression of fluorescently tagged, recombinant Rab13 and knockout of endogenous Rab13 were used to assess the roles of Rab13 GTPase in ciliogenesis and cilia function in mouse renal epithelial cell lines grown as monolayers and spheroids. Ciliary morphogenesis, cell polarity and growth were assessed by confocal imaging in live and fixed cells, while biochemical approaches were used to test cilia-dependent signalling and associated molecular pathways, along-with Rab13 expression, activation and effector functions.
Results
Our data show that Rab13 localises to the primary cilia of mouse kidney cells and Rab13 loss of function affects ciliogenesis in a variety of in vitro and in vivo models including zebrafish embryos. Characterisation of Rab13 knockout epithelial cells reveal altered cilia, the perturbation of ciliopathy-associated protein localisation, and the formation of dysmorphic renal spheroids. Rab13 knockout zebrafish embryos display a range of cilia-associated developmental defects and Rab13 expression is diminished in mouse PKD cells.
Conclusion
Here we reveal a novel cilia-associated role for Rab13 GTPase. Investigating the genes and molecules that contribute to the cilial landscape is important to improve knowledge, for potential translation and discovery of new therapeutic approaches for renal ciliopathies including PKD.
Funding
- Private Foundation Support