Journal Article

SAMBA, a plant-specific anaphase-promoting complex/cyclosome regulator is involved in early development and A-type cyclin stabilization

Van Leene, Jelle, Witters, Erwin, Vanhaeren, Hannes, De Milde, Liesbeth, Maleux, Katrien, Vercruysse, Leen, Van Montagu, Marc C. E, Inzé, Dirk, Gonzalez, Nathalie, Dhondt, Stijn, Remaut, Han, Mercier, Raphaël, Ferreira, Paulo C. G, Cromer, Laurence, Beemster, Gerrit T. S, De Jaeger, Geert, Eloy, Nubia B

2012

Overview

The anaphase-promoting complex/cyclosome (APC/C) is a large multiprotein E3 ubiquitin ligase involved in ubiquitin-dependent proteolysis of key cell cycle regulatory proteins, including the destruction of mitotic cyclins at the metaphase-to-anaphase transition. Despite its importance, the role of the APC/C in plant cells and the regulation of its activity during cell division remain poorly understood. Here, we describe the identification of a plant-specific negative regulator of the APC/C complex, designated SAMBA. In Arabidopsis thaliana , SAMBA is expressed during embryogenesis and early plant development and plays a key role in organ size control. Samba mutants produced larger seeds, leaves, and roots, which resulted from enlarged root and shoot apical meristems, and, additionally, they had a reduced fertility attributable to a hampered male gametogenesis. Inactivation of SAMBA stabilized A2-type cyclins during early development. Our data suggest that SAMBA regulates cell proliferation during early development by targeting CYCLIN A2 for APC/C-mediated proteolysis.

• Publisher: National Academy of Sciences,National Acad Sciences
• Subject: Amino Acid Sequence / Anaphase-Promoting Complex-Cyclosome / apical meristems / Arabidopsis - genetics / Arabidopsis - metabolism / Arabidopsis thaliana / Biological Sciences / Cell Cycle / Cell division / Cell growth / cell proliferation / cells / Cyclin A - chemistry / Cyclins / early development / embryogenesis / Embryonic growth stage / Fertility / Flowers & plants / gametogenesis / Gene expression / Gene Expression Regulation, Plant / Inactivation / Leaves / Life Sciences / males / Models, Biological / Models, Genetic / Molecular Sequence Data / mutants / Mutation / Phenotype / Phenotypes / Plant cells / plant development / Plant Leaves - metabolism / Plant Proteins - metabolism / Plant reproduction / Plants / Pollen / Pollen - metabolism / Proteins / proteolysis / roots / Samba / seeds / Sequence Homology, Amino Acid / shoots / ubiquitin-protein ligase / Ubiquitin-Protein Ligase Complexes - genetics / Ubiquitin-Protein Ligase Complexes - physiology