a. Heatmap showing the number of peptides of AR-cofactors and HDAC3/NCoR complex enriched by HOXB13 WT or G84E mutant mass spectrometry. The complete lists are included in Supplemental Table 6.
b-c. Co-IP of V5-NcoR1 full-length (FL) or deletion mutants (b) expressed in 293T cells along with HOXB13, with or without HDAC3 co-expression (c). Co-IP using whole-cell lysates showed no interactions between HOXB13 and NCoR1 in cells without HDAC3 co-expression.
d-e. Co-IP of HA-HDAC3 FL or deletion mutants (d) expressed in 293T cells along with HOXB13 (e). Whole-cell lysates were subjected to co-IP using an anti-HA antibody.
f. Fractionation assay showing cellular localization of HOXB13 WT and mutants in LNCaP cells. WT, G84E and ΔMEIS HOXB13 were detected on the chromatin, whereas ΔHOX and WFQ-3A have impaired ability to bind chromatin. Asterisk indicates endogenous HOXB13.
g-h. Schematic illustration of a series of HOXB13 deletion mutants (g) and their interaction with HDAC3 (h). Whole-cell lysates from 293T cells co-transfected with HA-HDAC3 along with Flag-tagged HOXB13 FL or its deletion mutants were subjected to co-IP using an anti-Flag antibody. Asterisk indicates the size of corresponding mutants.
i. The interaction between HOXB13 and MEIS1 is not interrupted by HDAC3. Whole-cell lysates from 293T cells co-transfected with Flag-HOXB13 along with HA-tagged MEIS1 and gradually increased amount of HA-tagged HDAC3 were subjected to co-IP using an anti-Flag antibody.