Figure 4.

A 179-aa region containing the N-terminal SANT domain is required for transcriptional repression. Cells were transfected with Gal4-VP16 expression constructs fused to nothing, full-length CoREST, or ΔNsant-F. Empty Gal4-VP16 is a potent transcriptional activator, and full-length CoREST is a potent transcriptional repressor. The repression by full-length CoREST is derepressed with TSA treatment. Relative to full-length CoREST, ΔNsant-f is derepressed, demonstrating that the HDAC-interacting region of the N-terminal SANT domain is required for full transcriptional repression.