Zhang, Xinchun , Orth, Travis , Reumann, Sigrun , Fan, Jilian , Wenzel, Dirk , Quan, Sheng , Aung, Kyaw , Hu, Jianping .
Toward understanding plant peroxisome proliferation.
Plant peroxisomes are essential to development and adapt to environmental changes by altering their abundance, yet the molecular basis for peroxisome proliferation has been largely unexplored. To establish a model for peroxisome proliferation in plants, we have employed forward and reverse genetics and performed proteomic analysis of the peroxisomal membrane. Except for Pex11p, which in yeast is involved in peroxisome proliferation with an unknown mechanism, the Arabidopsis genome does not contain obvious sequence homologues to most proteins that operate in yeast to control peroxisome proliferation. The five-member Arabidopsis PEX11 protein family is composed of three subfamilies: PEX11a, PEX11b, and PEX11c to PEX11e, all of which target to peroxisomes, as demonstrated by fluorescence microscopy and immunobiochemical analysis. Overexpression of At PEX11 genes in Arabidopsis induced peroxisome proliferation, whereas reduction in gene expression lowered peroxisome abundance. PEX11c and PEX11e complemented the growth phenotype of the S. cerevisiae pex11 null mutant on oleic acid. Our results suggested that the Arabidopsis PEX11 proteins promote peroxisome proliferation with some functional specificity between subfamilies (Orth et al. 2007 Plant Cell). We also identified a subset of the dynamin-related large GTPases that mediates the division of both peroxisomes and mitochondria, which indicated that despite their distinct evolutionary paths, these two types of organelles may use the same set of dynamin-related proteins (DRPs) for division. Additional forward genetic screens and proteomic experiments are conducted in the lab to uncover more plant-specific constituents of the peroxisome proliferation apparatus.
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1 - Michigan State University, MSU-DOE Plant Research Laboratory, East Lansing, MI, 48824, USA
2 - University of Göttingen, Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences
3 - Max Planck Institute for Biophysical Chemistry, Department of Neurobiology
peroxisome division and proliferation
dynamin-related proteins (DRPs).
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM