@article{WangLiMaetal.2021,
  author    = {Wang, Meng and Li, Panpan and Ma, Yao and Nie, Xiang and Grebe, Markus and Men, Shuzhen},
  title     = {Membrane sterol composition in Arabidopsis thaliana affects root elongation via auxin biosynthesis},
  series = {International journal of molecular sciences},
  volume    = {22},
  journal   = {International journal of molecular sciences},
  number    = {1},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {1422-0067},
  doi       = {10.3390/ijms22010437},
  pages     = {20},
  year      = {2021},
  abstract  = {Plant membrane sterol composition has been reported to affect growth and gravitropism via polar auxin transport and auxin signaling. However, as to whether sterols influence auxin biosynthesis has received little attention. Here, by using the sterol biosynthesis mutant cyclopropylsterol isomerase1-1 (cpi1-1) and sterol application, we reveal that cycloeucalenol, a CPI1 substrate, and sitosterol, an end-product of sterol biosynthesis, antagonistically affect auxin biosynthesis. The short root phenotype of cpi1-1 was associated with a markedly enhanced auxin response in the root tip. Both were neither suppressed by mutations in polar auxin transport (PAT) proteins nor by treatment with a PAT inhibitor and responded to an auxin signaling inhibitor. However, expression of several auxin biosynthesis genes TRYPTOPHAN AMINOTRANSFERASE OF ARABIDOPSIS1 (TAA1) was upregulated in cpi1-1. Functionally, TAA1 mutation reduced the auxin response in cpi1-1 and partially rescued its short root phenotype. In support of this genetic evidence, application of cycloeucalenol upregulated expression of the auxin responsive reporter DR5:GUS (beta-glucuronidase) and of several auxin biosynthesis genes, while sitosterol repressed their expression. Hence, our combined genetic, pharmacological, and sterol application studies reveal a hitherto unexplored sterol-dependent modulation of auxin biosynthesis during Arabidopsis root elongation.},
  language  = {en}
}
@article{FrescatadaRosaStanislasBackuesetal.2014,
  author    = {Frescatada-Rosa, Marcia and Stanislas, Thomas and Backues, Steven K. and Reichardt, Ilka and Men, Shuzhen and Boutte, Yohann and Juergens, Gerd and Moritz, Thomas and Bednarek, Sebastian York and Grebe, Markus},
  title     = {High lipid order of Arabidopsis cell-plate membranes mediated by sterol and Dynamin-Related Protein 1A function},
  series = {The plant journal},
  volume    = {80},
  journal   = {The plant journal},
  number    = {5},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {0960-7412},
  doi       = {10.1111/tpj.12674},
  pages     = {745 -- 757},
  year      = {2014},
  abstract  = {Membranes of eukaryotic cells contain high lipid-order sterol-rich domains that are thought to mediate temporal and spatial organization of cellular processes. Sterols are crucial for execution of cytokinesis, the last stage of cell division, in diverse eukaryotes. The cell plate of higher-plant cells is the membrane structure that separates daughter cells during somatic cytokinesis. Cell-plate formation in Arabidopsis relies on sterol- and DYNAMIN-RELATED PROTEIN1A (DRP1A)-dependent endocytosis. However, functional relationships between lipid membrane order or lipid packing and endocytic machinery components during eukaryotic cytokinesis have not been elucidated. Using ratiometric live imaging of lipid order-sensitive fluorescent probes, we show that the cell plate of Arabidopsis thaliana represents a dynamic, high lipid-order membrane domain. The cell-plate lipid order was found to be sensitive to pharmacological and genetic alterations of sterol composition. Sterols co-localize with DRP1A at the cell plate, and DRP1A accumulates in detergent-resistant membrane fractions. Modifications of sterol concentration or composition reduce cell-plate membrane order and affect DRP1A localization. Strikingly, DRP1A function itself is essential for high lipid order at the cell plate. Our findings provide evidence that the cell plate represents a high lipid-order domain, and pave the way to explore potential feedback between lipid order and function of dynamin-related proteins during cytokinesis.},
  language  = {en}
}