Arabidopsis 2010: Plant Peroxisomal Biogenesis: Sorting/Function of Membrane Proteins and Peroxins

Arizona State University, Scottsdale AZ

Investigators

Abstract

Title: "Arabidopsis 2010: Plant Peroxisomal Biogenesis - Sorting/Function of Membrane Proteins and Peroxins". Peroxisomes are ubiquitous subcellular organelles that possess a diverse array of enzymes and other protein contents that vary with developmental stage, and in response to environmental cues. The overall goal of this project is to identify Arabidopsis genes coding for peroxisomal membrane proteins (PMPs) involved in the biogenesis and functioning of peroxisomes, and then determine the specific function of the gene products. "Peroxin" genes code for a set of proteins (peroxins) that participate specifically in peroxisomal biogenesis (organelle replication and differentiation). Most peroxins are PMPs. To date, 15 Arabidopsis orthologs of 23 eukaryotic peroxin genes have been identified, but a function has been determined for only 4 of these 15 orthologs. Public access to this information will be available at (<A HREF="http://lsweb.la.asu.edu/rtrelease">http://lsweb.la.asu.edu/rtreleaseq</A>). The function(s) of these PMPs will be determined experimentally through a multi-pronged approach, i.e., elucidation of their subcellular localization, intracellular sorting pathways, and molecular sorting signals in suspension cells from wild type and mutant plants, and developmentally through interactions of RNAs with increasingly available ESTs on microarrays. Also, phenotypic and functional complementation results obtained with available T-DNA knockouts will be examined. Experimental results will be presented by students and postdoctoral persons attending local and national meetings, and will be published in refereed journal articles. The research is expected to elucidate the function of at least 10 genes related to the biogenesis and functioning of peroxisomes in Arabidopsis; this is consistent with the Objectives of the 2010 Project. Since peroxisomal mutations are lethal in humans, and peroxisomes are essential for seedling establishment and photo-autotrophic growth of oilseed and other crop plants, the knowledge obtained for functions of Arabidopsis peroxisomal genes can and very likely will be applied to biotechnological improvements of agriculturally-important crop plants, and to possibly speed therapeutic resolution of peroxisomal biogenetic diseases in human infants.