The C terminus of MINT forms homodimers and abrogates MINT-mediated transcriptional repression

Notch signaling plays a pivotal role in numerous cell fate determination events during development, and therefore its regulation has been studied intensively. MSX2-interacting nuclear target protein (MINT) modifies the Notch signaling by interacting with and inhibiting the downstream transcription factor RBP-J/CBF-1 of Notch. In this study, by a yeast two hybrid screening, we found that the C terminal fragment of MINT interacted with each other. We confirmed the interaction between two MINT C terminal fragments both in vitro and in vivo. We further demonstrated that the overexpression of the C terminal fragment of MINT cancelled its inhibitory effect on the transactivation of an RBP-J-dependent promoter by Notch. These results suggest that MINT may form a dimer or multimer in cells through its C terminus, and that the C terminal fragment of MINT may work as its dominant-negative version.