Journal Article

Arabidopsis ULTRAVIOLET-B-INSENSITIVE4 Maintains Cell Division Activity by Temporal Inhibition of the Anaphase-Promoting Complex/Cyclosome

Berckmans, Barbara, Verkest, Aurine, Koncz, Csaba, Kamel, Claire Lessa Alvim, De Veylder, Lieven, Van den Daele, Hilde, De Jaeger, Geert, Heyman, Jefri, De Wit, Kevin, Boudolf, Véronique

2011

Overview

The anaphase-promoting complex/cyclosome (APC/C) is a multisubunit ubiquitin ligase that regulates progression through the cell cycle by marking key cell division proteins for destruction. To ensure correct cell cycle progression, accurate timing of APC/C activity is important, which is obtained through its association with both activating and inhibitory subunits. However, although the APC/C is highly conserved among eukaryotes, no APC/C inhibitors are known in plants. Recently, we have identified ULTRAVIOLET-B-INSENSITIVE4 (UVI4) as a plant-specific component of the APC/C. Here, we demonstrate that UVI4 uses conserved APC/C interaction motifs to counteract the activity of the CELL CYCLE SWITCH52 A1 (CCS52A1) activator subunit, inhibiting the turnover of the A-type cyclin CYCA2;3. UVI4 is expressed in an S phase-dependent fashion, likely through the action of E2F transcription factors. Correspondingly, uvi4 mutant plants failed to accumulate CYCA2; 3 during the S phase and prematurely exited the cell cycle, triggering the onset of the endocycle. We conclude that UVI4 regulates the temporal inactivation of APC/C during DNA replication, allowing CYCA2;3 to accumulate above the level required for entering mitosis, and thereby regulates the meristem size and plant growth rate.

• Publisher: American Society of Plant Biologists
• Subject: Anaphase-promoting complex / Anaphase-Promoting Complex-Cyclosome / anatomy & histology / Arabidopsis / Arabidopsis - anatomy & histology / Arabidopsis - genetics / Arabidopsis - growth & development / Arabidopsis - metabolism / Arabidopsis Proteins / Arabidopsis Proteins - genetics / Arabidopsis Proteins - metabolism / Cell cycle / Cell Cycle Proteins / Cell Cycle Proteins - genetics / Cell Cycle Proteins - metabolism / Cell Differentiation / Cell Division / Chromatin Immunoprecipitation / Cyclin A2 / Cyclin A2 - genetics / Cyclin A2 - metabolism / Cyclin-Dependent Kinases / Cyclin-Dependent Kinases - genetics / Cyclin-Dependent Kinases - metabolism / Cyclins / DNA / DNA biosynthesis / DNA replication / E2F protein / E2F Transcription Factors / E2F Transcription Factors - genetics / E2F Transcription Factors - metabolism / Epidermal cells / eukaryotic cells / Gene expression regulation / Gene Expression Regulation, Plant / Genetic Complementation Test / genetics / growth & development / Growth rate / Inactivation / interphase / Meristem / Meristem - growth & development / Meristem - metabolism / Meristem - ultrastructure / Meristems / metabolism / Microscopy, Electron, Scanning / Mitosis / Mutagenesis, Site-Directed / Plant cells / Plant growth / Plant Leaves / Plant Leaves - genetics / Plant Leaves - growth & development / Plant Leaves - metabolism / Plants / Protein Interaction Domains and Motifs / Protein Stability / Replication / S Phase / Structure-Activity Relationship / Tetraploidy / Transcription factors / Transcriptional Activation / Transformation, Genetic / Trichomes / Two-Hybrid System Techniques / ubiquitin / Ubiquitin-protein ligase / Ubiquitin-Protein Ligase Complexes / Ubiquitin-Protein Ligase Complexes - genetics / Ubiquitin-Protein Ligase Complexes - metabolism / ultrastructure / Ultraviolet radiation