IκB Kinase ε Phosphorylates TRAF2 To Promote Mammary Epithelial Cell Transformation

• DOI: 10.1128/mcb.00468-12
• Publication Date: 2012-09-25T02:40:31Z
• Authors: Rhine R. Shen; Alicia Y. Zhou; Eejung Kim; Elgene Lim; Hasem Habelhah; William C. Hahn
• Keywords: 0301 basic medicine; NF-kappa B; Down-Regulation; RNA-Binding Proteins; Breast Neoplasms; Epithelial Cells; Deubiquitinating Enzyme CYLD; I-kappa B Kinase; Nuclear Pore Complex Proteins; Cysteine Endopeptidases; Mice; 03 medical and health sciences; Cell Transformation, Neoplastic; HEK293 Cells; Cell Line, Tumor; NIH 3T3 Cells; Animals; Humans; Female; Amino Acid Sequence; Breast; Phosphorylation

NF-κB transcription factors are central regulators of inflammation and when dysregulated contribute to malignant transformation. IκB kinase ε (IKKε; IKKi, encoded by IKBKE) is a breast oncogene that is amplified in 30% of breast cancers and drives transformation in an NF-κB-dependent manner. Here we demonstrate that IKKε interacts with and phosphorylates tumor necrosis factor receptor-associated factor 2 (TRAF2) at Ser11 in vitro and in vivo. This activity promotes Lys63-linked TRAF2 ubiquitination and NF-κB activation and is essential for IKKε transformation. Breast cancer cells that depend on IKKε expression for survival are also dependent on TRAF2. This work defines TRAF2 phosphorylation to be one key effector of IKKε-induced mammary epithelial cell transformation.