Investigating Ciliary Regulation Driven by the Centrosomal Kinase CSNK2A1 — 88p — Cecilia “Quinn” Tegenkamp, Elizabeth Menzel

The term “ciliopathy” refers to a category of diseases caused by dysfunctions which affect [CT1] the non-motile sensory organelle of primary cilium. This microtubule-based organelle detects extracellular stimuli [CT2], triggering the appropriate intracellular transcriptional [CT3]signal in response. Casein kinase II subunit alpha (CSNK2A1) has been previously identified as a novel modulator of primary cilia trafficking and stability at the basal body. While it mediates a wide range of ciliary functions, the underlying molecular mechanisms through which CSNK2A1 modulates cilia regulation are still unknown. Our preliminary results identified two potential downstream regulators, CCT2 and CCT5, two of the eight chaperonins of the TRiC complex. CSNK2A1 KO cells showed disrupted centrosome structures of both subunits. To test the requirements for this kinase activity, we employed two different CSNK2A1 inhibitors. The more specific CSNK2A1 inhibitor was found to affect CCT2 structure and level at the base of cilia, as imaged with super-resolution and widefield microscopy. While control cells exhibited a ring-like structure, drug-treated cells showed a disrupted CCT2 structure. However, this was not observed with CX4945, a less specific CSNK2A1 drug. To further resolve CCT structure at the basal body, we coupled expansion microscopy with super-resolution microscopy to reach a lateral resolution of about 40 nm. After a number of protocol adjustments, we successfully expanded the cells and imaged known ciliary (ARL13B) and centrosomal (Centrin-2) proteins at the desired resolution. 

Our research will lay the groundwork to better understand cilia regulation and the specific molecular dynamics occurring at the cilia-centrosome interface: the modulator of cilia function and homeostasis.

Sanford Research
Abdelhalim Loukil