Thirty public domain ChIP-Seq raw data sets in mouse ES cells were obtained from Gene Expression Omnibus (GEO) [ 92]: 12 TFs [ 5], 8 histone modifications [ 29], 3 polymerase occupancy [ 30] and 7 chromatin associated proteins [ 5, 22, 28] (Table 1).
The K30A point mutation within the TPR domain of CHIP that blocks CHIP binding to Hsp90 [37] also blocks binding of the isolated TPR domain to the N-terminus of LRRK2 (Supplemental Figure S2C, D).
The above data shows that the TPR domain of CHIP is required for CHIP to bind to the N-terminal portion of LRRK2.
Because the U-box domain of CHIP is also dispensable (Figure 2D), the intervening charged domain of CHIP appears to be sufficient for CHIP to interact with the C-terminal portion of LRRK2.
Because we found that the N-terminal chaperone interaction (TPR) domain of CHIP and the C-terminal U-box domain of CHIP are not essential for binding to LRRK2 (Figure 2), we examined whether these domains of CHIP are required for CHIP-mediated LRRK2 degradation.
The combined data shown in Figure 1 and Figure 2 indicate that the charged domain of CHIP binds to the ROC domain of LRRK2 and that the TPR domain of CHIP is required for binding to the N-terminal region of LRRK2 that includes the armadillo, ankyrin and leucine-rich repeats.
This is the first demonstration that the charged domain of CHIP directly binds to another protein.
