Identification of DNA-dependent protein kinase catalytic subunit as a novel interaction partner of lymphocyte enhancer factor 1
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Lymphocyte enhancer factor 1 (LEF1), a member of the LEF/T-cell-specific factor (TCF) family of the high mobility group domain transcription factors, acts downstream in canonical Wnt signaling. Aberrant transactivation of LEF1 contributes to the tumorigenesis of colonic neoplasms, sebaceous skin tumors, and lymphoblastic leukemia. LEF1-associated proteins are crucial for regulating its transcriptional activity. In this study, glutathione-S-transferase pull-down assay and mass spectrometry enabled identification of the DNA-dependent protein kinase catalytic subunit (DNA-PKcs) as a novel interaction partner for LEF1. The interaction between LEF1 and DNA-PKcs was confirmed using in vivo co-immunoprecipitation. Furthermore, double immunofluorescence observations showed that LEF1 and DNA-PKcs colocalized in the nuclei of colon adenocarcinoma cell lines. Identification of the interaction between LEF1 and DNA-PKcs may provide clues for a novel therapy for cancer treatment as well as for understanding LEF1-mediated transcriptional regulation.
KeywordsDNA-dependent catalytic subunit (DNA-PKcs) Lymphocyte enhancer factor 1 (LEF-1) Novel interaction partner Colon adenocarcinoma cell Thymus Glutathione-S-transferase pull-down assay Mass spectrometry
We thank Kazuhiro Yanagisawa, Yohei Takeuchi, and Kazuko Hikita from the Department of Anatomy I, Fujita Health University School of Medicine, for their technical and secretarial assistance. This work was supported by a Grant-in-Aid from JSPS KAKENHI Grant Number 24592567 and by grants from the Promotion and Mutual Aid Corporation for Private Schools of Japan and from the Fujita Health University Research Fund.
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