International Immunology Advance Access published online on January 29, 2008
International Immunology, doi:10.1093/intimm/dxm154
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BART is essential for nuclear retention of STAT3
Department of Immunology, Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita-Ku Kita 12 Nishi 6, Sapporo, Hokkaido 060-0812, Japan
Correspondence to: Correspondence to: T. Matsuda; E-mail: tmatsuda{at}pharm.hokudai.ac.jp
Signal transducers and activators of transcription (STATs) mediate cell proliferation, differentiation and survival in immune responses, hematopoiesis, neurogenesis and other biological processes. STAT3, for example, is involved in the epithelial–mesenchymal transition during gastrulation, organogenesis, wound healing and cancer progression. STAT activity is regulated by a variety of mechanisms, including nuclear translocation. To clarify the molecular mechanisms underlying the regulation of STAT activity, we performed yeast two-hybrid screening. Here, we identified binder of ADP-ribosylation factor-like two (BART) as a novel STAT-binding partner. Importantly, we showed that BART is essential for the transcriptional activity and nuclear retention of STAT3. Furthermore, an effector of BART, ADP-ribosylation factor-like 2 (ARL2) was also involved in nuclear retention of STAT3. These results indicate that BART plays an essential role in the nuclear retention of STAT3 through interaction with ARL2.
Keywords: BART, IL-6, LIF, nuclear retention, signal transduction, STAT3
* These authors contributed equally to this study.
Transmitting editor: T. Hirano
Received 6 November 2007, accepted 28 December 2007.