TRIM24 is a multi-functional chromatin reader, and it binds to the estrogen receptor to
activate estrogen-dependent target genes associated with tumor development. TRIM24 is
known to ubiquitinate p53 via an N-terminal RING domain and binds a specific
combinatorial histone signature of H3K4me0/H3K23ac via its C-terminal plant
homeodomain (PHD) and bromodomain (Bromo). Aberrant expression of TRIM24 positively
correlates with H3K23ac levels, and high levels of both TRIM24 and H3K23ac predict poor …

IQGAP1 is a scaffold protein for both the RAS/MAP kinase and PI 3-kinase signalling
pathways, as shown on the right. Its WW domain, modelled on the left, has anti-tumour
activity when engineered as a cell-penetrating peptide. The study by Bardwell and
colleagues (pp. 729–750) shows that the catalytic subunit of PI 3-kinase, a known driver
oncogene, is a direct binding partner of the WW domain, which could help explain its anti-
tumour properties. The image was provided by Lee Bardwell.