Protein disulfide isomerases (PDIs) contain thioredoxin domains and aid in the formation of proper disulfide bonds during protein folding. Iterative BLAST searches of sequence databases were used to identify 22 PDI-like (PDIL) genes in Arabidopsis thaliana and maize (Zea mays) and 19 in rice (Oryza sativa). The PDIL genes were resolved into 10 phylogenetic groups. Genes in groups I-V had two active thioredoxin domains while members of groups VI-X had one active thioredoxin domain. One single domain PDIL, maize PDIL5-1, showed increased accumulation in the endosperm mutants that produced defective storage proteins, but PDIL5-1 was not localized to endomembrane fractions. Expression analysis was done in eighteen PDIL genes in maize endosperm, a storage tissue, and two vegetative organs, embryo and leaves. Eight PDIL genes were expressed mainly in endosperm, and two of these genes (PDIL1-2 and 2-3) had increased expression levels only in the endosperm that produced defective storage proteins. There were three PDIL genes (1-3, 1-4, 1-5) that showed the highest expression levels in the embryo, while two other genes, adenosine 5?-phosphosulfate reductase-like (APRL) 2 and APRL8, had elevated expression levels in leaves. To further characterize members of the gene family, isomerase and reductase assays were conducted to test for recombinant maize PDIL1-1, 1-3, 2-3 and 5-1 enzymatic activity in vitro. Recombinant and endogenous maize PDIL1-1 showed both isomerase and reductase activity while recombinant PDIL1-3 showed anti-chaperone activity. Recombinant PDIL2-3 and PDIL5-1 showed no activity under the assay conditions tested.
| Identifer | oai:union.ndltd.org:NCSU/oai:NCSU:etd-06062007-230831 |
| Date | 15 June 2007 |
| Creators | Houston, Norma L |
| Contributors | Wendy Boss, Heike Winter - Sederoff, Rebecca S Boston, Jenny Xiang |
| Publisher | NCSU |
| Source Sets | North Carolina State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://www.lib.ncsu.edu/theses/available/etd-06062007-230831/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dis sertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to NC State University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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