The immune synapse (IS) is the nano-scale gap formed at the interface between T cells and antigen-presenting cells (APCs) when T cell receptors (TCRs) bind the MHC complexes associated with antigens. An important step in IS assembly that ensures sustained signalling is the repositioning of the centrosome in the T cell towards the APC, together with the Golgi complex and endosomal recycling compartment, allowing polarised transport of TCRs and other signalling proteins. Previously, the team of Cosima Baldari showed that ciliary intraflagellar transport (IFT) proteins are co-opted for polariSed recycling at the IS. Now, a study by the same group (Cassioli et al., 2021) identifies the ciliary protein BBS1, a core component of the Bardet–Biedl syndrome complex, as a new player in IS assembly. The authors show that BBS1 promotes the proteasome-dependent clearance of F-actin and its regulator the WASH complex around the centrosome, which is important for detachment of the centrosome from the nucleus and its mobiliSation towards the IS. Mechanistically, BBS controls this process by coupling the 19S regulatory unit of the proteasome to the molecular motor dynein for vesicular transport to the centrosome. These new insights into IS assembly may also have implications for understanding how adaptive immunity is affected in patients with BBS mutations.