Homodimer (By similarity). Interacts with BAG2, and with the E2 ubiquitin conjugating enzymes UBE2D1, UBE2D2 and UBE2D3. Interacts with the C-terminal domains of HSPA8 and HSPA1A. Detected in a ternary complex containing STUB1, HSPA1A and HSPBP1 (By similarity).