Null mutation of AtCUL1 causes arrest in early embryogenesis in Arabidopsis

• Published in: Molecular biology of the cell Vol. 13; no. 6; pp. 1916 - 1928
• Main Authors: Shen, Wen-Hui, Parmentier, Yves, Hellmann, Hanjo, Lechner, Esther, Dong, Aiwu, Masson, Jean, Granier, Fabienne, Lepiniec, Loïc, Estelle, Mark, Genschik, Pascal
• Format: Journal Article
• Language: English
• Published: United States American Society for Cell Biology 01-06-2002; The American Society for Cell Biology
• Subjects: Amino Acid Sequence; Arabidopsis; Arabidopsis - embryology; Arabidopsis - genetics; Arabidopsis - physiology; Arabidopsis Proteins - chemistry; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Cell Cycle Proteins - chemistry; Cell Cycle Proteins - genetics; Cell Cycle Proteins - metabolism; Cell Nucleus - ultrastructure; Cullin Proteins; Cytoplasm - ultrastructure; Gene Deletion; Genetic Vectors; Life Sciences; Metaphase; Molecular Sequence Data; Morphogenesis; Recombinant Proteins - chemistry; Recombinant Proteins - metabolism; Reproduction - genetics; Reproduction - physiology; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - physiology; Saccharomyces cerevisiae Proteins; Sequence Alignment; Sequence Homology, Amino Acid; Spindle Apparatus - ultrastructure; Transformation, Genetic; s-phase; cycle-dependent proteolysis; f-bauxin response; proteasome gene family; thaliana; cop9 signalosome; SCF; tobacco by2 cells; degradation; ox protein; higher-plants
• ISSN: 1059-1524; 1939-4586
• DOI: 10.1091/mbc.E02-02-0077

The SCF (for SKP1, Cullin/CDC53, F-box protein) ubiquitin ligase targets a number of cell cycle regulators, transcription factors, and other proteins for degradation in yeast and mammalian cells. Recent genetic studies demonstrate that plant F-box proteins are involved in auxin responses, jasmonate signaling, flower morphogenesis, photocontrol of circadian clocks, and leaf senescence, implying a large spectrum of functions for the SCF pathway in plant development. Here, we present a molecular and functional characterization of plant cullins. The Arabidopsis genome contains 11 cullin-related genes. Complementation assays revealed that AtCUL1 but not AtCUL4 can functionally complement the yeast cdc53 mutant. Arabidopsis mutants containing transfer DNA (T-DNA) insertions in the AtCUL1 gene were shown to display an arrest in early embryogenesis. Consistently, both the transcript and the protein of the AtCUL1 gene were found to accumulate in embryos. The AtCUL1 protein localized mainly in the nucleus but also weakly in the cytoplasm during interphase and colocalized with the mitotic spindle in metaphase. Our results demonstrate a critical role for the SCF ubiquitin ligase in Arabidopsis embryogenesis.