a, IP of endogenous APC3 from HeLa cells reveals that APC/C binds WDR5 and TBP in mitosis. Prometaphase HeLa cells were released into fresh medium to restart the cell cycle. This experiment was performed three independent times with similar results.
b, IP of endogenous WDR5 from HeLa cells confirms that WDR5 associates with APC/C subunits and TBP in mitosis. This experiment was performed three independent times with similar results.
c, Sequential IPs of APC/C-FLAGWDR5 complexes from mitotic 293T cells reveal that APC/CWDR5 and TBP form a ternary complex. FLAGWDR5 was first purified from prometaphase cells and next purified with αAPC3. This experiment was performed once.
d, Endogenous APC3 IPs from control versus WDR5-depleted hESCs show that APC/C’s association with TBP is bridged through WDR5. This experiment was performed twice with similar results.
e, ~20 Å negative-stain electron microscopy model corroborates WDR5’s association with the catalytic core of the APC/C.
f,
FLAGWDR5 purified from mitotic HeLa cells contains active APC/C. FLAGWDR5 or FLAGWDR5ΔWIN were purified from mitotic HeLa cells and incubated with E1, UBE2C, UBE2S, ubiquitin, ATP, and 35S-labeled geminin. This experiment was performed two independent times with similar results.