The Ccl1–Kin28 kinase complex regulates autophagy under nitrogen starvation
Date of Issue2016
School of Biological Sciences
Starvation triggers global alterations in the synthesis and turnover of proteins. Under such conditions, the recycling of essential nutrients by using autophagy is indispensable for survival. By screening known kinases in the yeast genome, we newly identified a regulator of autophagy, the Ccl1–Kin28 kinase complex (the equivalent of the mammalian cyclin-H–Cdk7 complex), which is known to play key roles in RNA-polymerase-II-mediated transcription. We show that inactivation of Ccl1 caused complete block of autophagy. Interestingly, Ccl1 itself was subject to proteasomal degradation, limiting the level of autophagy during prolonged starvation. We present further evidence that the Ccl1–Kin28 complex regulates the expression of Atg29 and Atg31, which is crucial in the assembly of the Atg1 kinase complex. The identification of this previously unknown regulatory pathway sheds new light on the complex signaling network that governs autophagy activity.
Journal of Cell Science
© 2016 The Author(s) (published by The Company of Biologists Ltd). This paper was published in Journal of Cell Science and is made available as an electronic reprint (preprint) with permission of The Author(s) (published by The Company of Biologists Ltd). The published version is available at: [http://dx.doi.org/10.1242/jcs.177071]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.