Akt1-Mediated Phosphorylation of RBP-Jk Controls Notch1 Signaling

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M.-Y. Kim^1,a, J. Y. Park¹, and H.-S. Park^1,b*

¹School of Biological Sciences and Technology, Chonnam National University, 61186 Gwangju, Republic of Korea

^* To whom correspondence should be addressed.

Received May 31, 2019; Revised July 17, 2019; Accepted July 17, 2019

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The Notch1 signaling pathway plays a crucial role in determining cell fate, including cell growth and differentiation. In this study, we demonstrated that the antagonistic action of RTK (receptor tyrosine kinase) signaling pathway on the Notch1 signaling pathway is mediated via Ras-PI3K-Akt1. The PI3K-Akt1 signaling pathway was shown to inhibit Notch1 signaling via phosphorylation of RBP-Jk. We observed not only reduced association between Notch1 and RBP-Jk, but also suppression of the Notch1 transcriptional activity. Our results demonstrated that Akt1 functions as a natural inhibitor of the Notch1 signaling pathway via phosphorylation of RBP-Jk.

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KEY WORDS: Notch1 signaling pathway, Akt1, phosphorylation

DOI: 10.1134/S0006297919120137

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