Structural and calorimetric studies demonstrate that the hepatocyte nuclear factor 1? (HNF1?) transcription factor is imported into the nucleus via a monopartite NLS sequence.

ABSTRACT: The transcription factor hepatocyte nuclear factor 1? (HNF1?) is ubiquitously overexpressed in ovarian clear cell carcinoma (CCC) and is a potential therapeutic target. To explore potential approaches that block HNF1? transcription we have identified and characterised extensively the nuclear localisation signal (NLS) for HNF1? and its interactions with the nuclear protein import receptor, Importin-?. Pull-down assays demonstrated that the DNA binding domain of HNF1? interacted with a spectrum of Importin-? isoforms and deletion constructs tagged with eGFP confirmed that the HNF1? (229)KKMRRNR(235) sequence was essential for nuclear localisation. We further characterised the interaction between the NLS and Importin-? using complementary biophysical techniques and have determined the 2.4Å resolution crystal structure of the HNF1? NLS peptide bound to Importin-?. The functional, biochemical, and structural characterisation of the nuclear localisation signal present on HNF1? and its interaction with the nuclear import protein Importin-? provide the basis for the development of compounds targeting transcription factor HNF1? via its nuclear import pathway.

SUBMITTER: Wiedmann MM 

PROVIDER: S-EPMC4991853 | biostudies-literature | 2016 Sep

REPOSITORIES: biostudies-literature