UPDATES

6/2008: We have purified large amounts of glyoxysomes and gerontosomes and initiated proteomic analyses of these two peroxisomal variants. Subcellular targeting of a subset of proteins identified from both in silico Peroxisome Targeting Signal (PTS) searches and proteomic analysis of leaf peroxisomes has been done by co-expression of a peroxisomal marker protein (CFP-PTS1) and a YFP-fusion of each novel protein in tobacco leaves. Over 50% of the proteins tested were confirmed to be peroxisomal. We have also initiated identification and characterization of T-DNA insertion mutants for newly identified peroxisome genes. Follow-up studies of the physiological roles for some novel peroxisomal proteins have also been initiated.

12/2007: We have purified large quantities of leaf peroxisomes and identified peroxisomal proteins through one-dimensional gel electrophoresis followed by liquid chromatography- electrospray ionization- tandem mass spectrometry (1D GE-LC-ESI-MS/MS). We were able to identify over 150 peroxisomal proteins (known and putative), including nearly all of the known leaf peroxisomal matrix proteins and over 60 novel proteins.

6/2007: We have initiated purification and proteomic analysis of green leaf peroxisomes. We have also finished Gateway-compatible YFP reporter vector construction and the cloning of the first group of putative peroxisomal proteins into the YFP vectors. A number of the novel proteins identified from in silico and proteomics analyses were successfully confirmed to be peroxisome targeting.

10/2006: Project begins.