The anaphase-promoting complex is a dual integrator that regulates both MicroRNA-mediated transcriptional regulation of cyclin B1 and degradation of Cyclin B1 during Arabidopsis male gametophyte development.
|Title||The anaphase-promoting complex is a dual integrator that regulates both MicroRNA-mediated transcriptional regulation of cyclin B1 and degradation of Cyclin B1 during Arabidopsis male gametophyte development.|
|Publication Type||Journal Article|
|Year of Publication||2011|
|Authors||Zheng B, Chen X, McCormick S|
|Date Published||2011 Mar|
|Keywords||Amino Acid Sequence, Anaphase-Promoting Complex-Cyclosome, Arabidopsis, Arabidopsis Proteins, Cyclin B, Gene Expression Regulation, Plant, Genetic Pleiotropy, MicroRNAs, Mitosis, Molecular Sequence Data, Phenotype, Plant Leaves, Plants, Genetically Modified, Point Mutation, Pollen, Regulatory Elements, Transcriptional, RNA Polymerase II, RNA, Plant, Saccharomyces, Transcription Factors, Ubiquitin-Protein Ligase Complexes|
The anaphase-promoting complex/cyclosome (APC/C), an essential ubiquitin protein ligase, regulates mitotic progression and exit by enhancing degradation of cell cycle regulatory proteins, such as CYCB1;1, whose transcripts are upregulated by DUO POLLEN1 (DUO1). DUO1 is required for cell division in male gametophytes and is a target of microRNA 159 (miR159) in Arabidopsis thaliana. Whether APC/C is required for DUO1-dependent CYCB1;1 regulation is unknown. Mutants in both APC8 and APC13 had pleiotrophic phenotypes resembling those of mutants affecting microRNA biogenesis. We show that these apc/c mutants had reduced miR159 levels and increased DUO1 and CYCB1;1 transcript levels and that APC/C is required to recruit RNA polymerase II to MIR159 promoters. Thus, in addition to its role in degrading CYCB1;1, APC/C stimulates production of miR159, which downregulates DUO1 expression, leading to reduced CYCB1;1 transcription. Both MIR159 and APC8-yellow fluorescent protein accumulated in unicellular microspores and bicellular pollen but decreased in tricellular pollen, suggesting that spatial and temporal regulation of miR159 by APC/C ensures mitotic progression. Consistent with this, the percentage of mature pollen with no or single sperm-like cells increased in apc/c mutants and plants overexpressing APC8 partially mimicked the duo1 phenotype. Thus, APC/C is an integrator that regulates both microRNA-mediated transcriptional regulation of CYCB1;1 and degradation of CYCB1;1.
|Alternate Journal||Plant Cell|
|PubMed Central ID||PMC3082252|
|Grant List||GM61146 / GM / NIGMS NIH HHS / United States |
R01 GM061146 / GM / NIGMS NIH HHS / United States