Protein Modification and Turnover
Lopez, Harry , Gillikin, Jeff , Boston, Rebecca .
Characterization of Ubiquitin Fusion Degradation Protein (Ufd1) Accumulation in Maize and Arabidopsis.
Quality control in the endoplasmic reticulum (ER) relies in part on moving misfolded proteins from the ER to the cytosol for degradation. This process, known as ER-associated degradation (ERAD), requires retrotranslocation of the degradation substrate and subsequent delivery to the proteasome. As part of a larger goal to characterize the multiprotein machinery responsible for early ERAD steps, we used bioinformatic tools to identify a putative maize homolog of ubiquitin fusion degradation protein (Ufd1), a cytosolic protein implicated in other systems in the ERAD process. A partial coding region from a maize Ufd1 cDNA clone was introduced into an E. coli expression vector to produce a fusion protein that was purified and used for antibody production. Antibodies showed strong cross-reaction with recombinant Ufd1 protein from both maize and Arabidopsis as well as specificity for a band of the expected size in immunoblots of plant extracts. Ufd1 accumulation was characterized by comparing predictions from mRNA expression data with signals from immunoblots of different plant organs. To assay for changes in Ufd1 accumulation during ERAD, we used maize lines that synthesize mutant storage proteins and show induction of both molecular chaperones and components of the ERAD machinery. Endosperm tissue from seeds with the normal complement of storage proteins was compared with that from mutants for Ufd1, molecular chaperones and mitochondrial protein controls over a time course of seed development. Supported by the NSF-AGEP program, the RISE program at UPR-Cayey and the U.S. Dept. of Energy.
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1 - Univeristy of Puerto Rico at Cayey, Biology, Box 664, Naranjito, PR, 00719, Puerto Rico
2 - North Carolina State University, Plant Biology, Box 7612, Raleigh, NC, 27695, USA
Ubiquitin Fusion Degradation (Ufd1) protein.
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM