PT - JOURNAL ARTICLE AU - Hui Dong AU - Jack Dumenil AU - Fu-Hao Lu AU - Li Na AU - Hannes Vanhaeren AU - Christin Naumann AU - Maria Klecker AU - Rachel Prior AU - Caroline Smith AU - Neil McKenzie AU - Gerhard Saalbach AU - Liangliang Chen AU - Tian Xia AU - Nathalie Gonzalez AU - Mathilde Seguela AU - Dirk Inze AU - Nico Dissmeyer AU - Yunhai Li AU - Michael W. Bevan TI - Ubiquitylation activates a peptidase that promotes cleavage and destabilization of its activating E3 ligases and diverse growth regulatory proteins to limit cell proliferation in Arabidopsis AID - 10.1101/090563 DP - 2016 Jan 01 TA - bioRxiv PG - 090563 4099 - http://biorxiv.org/content/early/2016/11/30/090563.short 4100 - http://biorxiv.org/content/early/2016/11/30/090563.full AB - The characteristic shapes and sizes of organs are established by cell proliferation patterns and final cell sizes, but the underlying molecular mechanisms coordinating these are poorly understood. Here we characterize a ubiquitin-activated peptidase called DA1 that limits the duration of cell proliferation during organ growth in Arabidopsis thaliana. The peptidase is activated by two RING E3 ligases, BB and DA2, which are subsequently cleaved by the activated peptidase and destabilized. In the case of BB, cleavage leads to destabilization by the RING E3 ligase PRT1 of the N-end rule pathway. DA1 peptidase activity also cleaves the de-ubiquitylase UBP15, which promotes cell proliferation, and the transcription factors TCP15 and TCP22, which promote cell proliferation proliferation and repress endoreduplication. We propose that DA1 peptidase activity regulates the duration of cell proliferation and the transition to endoreduplication and differentiation during organ formation in plants by coordinating the destabilization of regulatory proteins.