Abstract:
COUP-TF interacting protein 1 (CTIP1) is a novel C2H2 zinc finger protein that mediates transcriptional repression of ARP1, a member of the COUP-TF subfamily of orphan nuclear receptors [1]. Here we show that CTIP1 interacts with heterochromatin-associated protein 1 (HP1) in vitro and in cells. This
interaction suggests the existence of a novel mechanism of transcriptional repression for COUP-TFs, which may involve association with heterochromatin. Analysis of in vitro interaction of different CTIPI deletion mutants with HP1 reveals that the amino terminal region of CTIP1 as well as the central core interact with HP1. These two domains were previously shown to mediate transcriptional repression when fused to GAL4 DBD [1] suggesting that association with HP1 proteins may be implicated in the repression function.
