title: KyoT3, an isoform of murine FHL1, associates with the transcription factor RBP-J and represses the RBP-J-mediated transactivation.
abstract: Previously, we have shown that KyoT2, an isoform of the four and a half LIM domain protein 1 (FHL1), modulates Notch signaling via repressing RBP-J-mediated transactivation. In this study, we investigated the effect of another isoform of FHL1, KyoT3, on transactivation of a RBP-J-dependent promoter. We found that KyoT3 was expressed widely in a variety of tissues. By constructing EGFP fusion proteins, we showed that KyoT3 locates preferentially in nucleus. KyoT3 interacted with RBP-J, as shown by co-immunoprecipitation assays. Moreover, we demonstrated by a reporter assay that KyoT3 repressed transactivation of a RBP-J-dependent promoter, which was activated by both the Notch intracellular domain and Epstein-Barr virus nuclear antigen 2, an EB virus-encoded oncoprotein. These results suggest a multi-elemental control of the Notch signaling pathway, which is critical for cell differentiation in development.
authors.affiliation: State Key Laboratory of Cancer Biology, Department of Medical Genetics and Developmental Biology, Fourth Military Medical University, Xi'an 710032, PR China.
authors.forename: Liang
authors.initials: L
authors.lastname: Liang
authors.forename: Hong-Wei
authors.initials: HW
authors.lastname: Zhang
authors.forename: Jie
authors.initials: J
authors.lastname: Liang
authors.forename: Xiao-Li
authors.initials: XL
authors.lastname: Niu
authors.forename: Su-Zhen
authors.initials: SZ
authors.lastname: Zhang
authors.forename: Lei
authors.initials: L
authors.lastname: Feng
authors.forename: Ying-Min
authors.initials: YM
authors.lastname: Liang
authors.forename: Hua
authors.initials: H
authors.lastname: Han