The p53-induced mouse zinc finger protein wig-1 binds double-stranded RNA with high affinity.
The p53-induced mouse wig-1 gene encodes a Cys2His2-type zinc finger protein of unknown function. The zinc fingers in wig-1 are connected by long (56-75) amino acid linkers. This distribution of zinc finger domains resembles that of the previously described double-stranded (ds)RNA-binding proteins dsRBP-ZFa and JAZ. Ectopically expressed FLAG-tagged mouse wig-1 protein localized to nuclei and in some cells to nucleoli, whereas GFP-tagged mouse wig-1 localized primarily to nucleoli. Electrophoretic mobility shift assay using a recombinant GST-wig-1 fusion protein showed that wig-1 preferentially binds dsRNA rather than single-stranded RNA or dsDNA. A set of deletion/truncation mutants of wig-1 was tested to determine the dsRNA-binding domain(s) or region(s) in wig-1 that is involved in the stabilization of wig-1-dsRNA complexes in vitro. This revealed that the first zinc finger in wig-1 is essential for binding to dsRNA, whereas zinc fingers 2 and 3 are dispensable. wig-1 protein expressed in mammalian cells also showed a high affinity for dsRNA. wig-1 represents the first confirmed p53-induced gene that encodes a dsRNA-binding protein. This suggests that dsRNA binding plays a role in the p53-dependent stress response.
Méndez-Vidal
Cristina
C
Karolinska Institute, Department of Oncology-Pathology, Cancer Center Karolinska, Karolinska Hospital, S-171 76 Stockholm, Sweden.
Wilhelm
Margareta T
MT
Hellborg
Fredrik
F
Qian
Wang
W
Wiman
Klas G
KG
D016475:3T3 Cells; D000818:Animals; D002466:Cell Nucleolus / Q000737:chemistry; D002467:Cell Nucleus / Q000737:chemistry; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*; D051379:Mice; D009687:Nuclear Proteins; D012330:RNA, Double-Stranded / Q000378:metabolism*; D016601:RNA-Binding Proteins; D015533:Transcriptional Activation; D016159:Tumor Suppressor Protein p53 / Q000502:physiology; D016335:Zinc Fingers
D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D012330:RNA, Double-Stranded; D016601:RNA-Binding Proteins; D016159:Tumor Suppressor Protein p53; C491518:Wig1 protein, mouse