The chaperonin complex TRiC/CCT is needed for the proper folding of all five G-protein beta subunits (Wells et al. 2006). TRiC/CCT cooperates with the phosducin-like protein PDCL (commonly known as PhLP or PhLP1), which interacts with both TRiC/CCT and G-protein beta subunits 1-5 (GNB1, GNB2, GNB3, GNB4, GNB5) (Dupre et al. 2007, Howlett et al. 2009). PDCL enables completion of G-protein beta folding by TRiC/CCT, promotes release of folded G-protein beta subunits 1-4 (GNB1, GNB2, GNB3, GNB4) from the chaperonin complex, and facilitates the formation of the heterodimeric G-protein beta:gamma complex between G-protein beta subunits 1-4 and G-protein gamma subunits 1-12 (Lukov et al. 2005, Lukov et al. 2006, Howlett et al. 2009, Lai et al. 2013, Plimpton et al. 2015, Xie et al. 2015). In the case of G-protein beta 5 (GNB5), PDCL stabilizes the interaction of GNB5 with the TRiC/CCT and promotes GNB5 folding, thus positively affecting formation of GNB5 dimers with RGS family proteins (Howlett et al. 2009, Lai et al. 2013, Tracy et al. 2015). However, over-expression of PDCL interferes with formation of GNB5:RGS dimers as PDCL and RGS proteins bind to the same regions of the GNB5 protein (Howlett et al. 2009).