May act as a co-chaperone for HSP90AB1 (By similarity). Interacts (via TPR repeats) with HSP90AB1 (By similarity). Interacts with HSPA8, CDC6, TBK1 and MSL1 (By similarity). Predominantly nuclear in the G1 and S phases of cell cycle and is evenly distributed between the nucleus and cytoplasm in the G2 phase. MSL1 can promote its nuclear localization (By similarity). Belongs to the TTC4 family.