Study of zein protein body formation in a heterologous system (Xenopus laevis oocyte)

Simple item page
dc.contributor.authorLee, Dong-Heeen
dc.contributor.committeechairPedersen, K.en
dc.contributor.committeememberEsen, Asimen
dc.contributor.committeememberHa, S.A.en
dc.contributor.committeememberLarson, Timothy J.en
dc.contributor.committeememberTurner, Bruceen
dc.contributor.departmentBiologyen
dc.date.accessioned2014-03-14T21:20:43Zen
dc.date.adate2005-10-10en
dc.date.available2014-03-14T21:20:43Zen
dc.date.issued1992-10-05en
dc.date.rdate2005-10-10en
dc.date.sdate2005-10-10en
dc.description.abstractMost seed storage proteins accumulate in protein bodies which are derived from the vacuole. Zeins, the major corn storage proteins, however, are retained in the endoplasmic reticulum (ER) and their protein bodies are derived from the ER. There are circumstantial and preliminary data indicating that 27K zein, the proline-rich zein, may span the ER membrane. This potential transmembrane feature is considered very significant to understand the mechanism for zeins' ER retention. The transmembrane feature may retain the 27K zein in the ER where it could serve as an anchor for other classes of zein through specific protein interactions. In this study, a heterologous system (<i>Xenopus laevis</i> oocytes) was used to investigate the potential transmembrane domain of 27K zein. This study utilized physical assays of proteolytic digestion (proteinase K) and chemical modification (biotinylation) on isolated protein vesicles from <i>Xenopus</i> oocytes injected with <i>in vitro</i> transcribed 27K zein mRNA. In addition, the transmembrane features were analyzed by monitoring the protein's mobility in the lumen of the ER by pulse-chase experiments. The results showed that the possibility of 27K zein as a transmembrane protein was consistently refuted in this study. The 27K zein protein was not affected by the proteinase K treatment or biotinylation. Moreover, 27K zein and total zeins moved freely in the lumen of the ER similar to a secretory protein (ovalbumin), totally different from an ER membrane protein (a mutant transmembrane hemagglutinin envelope protein). The free movement, within the ER lumen, of total zeins under conditions where zein aggregates should form necessitates a reevaluation of the mechanisms responsible for zein polypeptides' ER retention and protein body formation. This study, therefore, concludes that 27K zein is not a protein body nucleating factor by virtue of an ER transmerrlbrane feature or association with the ER membrane and that the significance of zein solubility should be reconsidered to explain the zeins' ER retention leading to protein body formation in the ER.en
dc.description.degreePh. D.en
dc.format.extentvii, 118 leavesen
dc.format.mediumBTDen
dc.format.mimetypeapplication/pdfen
dc.identifier.otheretd-10102005-131559en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-10102005-131559/en
dc.identifier.urihttp://hdl.handle.net/10919/39717en
dc.language.isoenen
dc.publisherVirginia Techen
dc.relation.haspartLD5655.V856_1992.L425.pdfen
dc.relation.isformatofOCLC# 27880800en
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subject.lccLD5655.V856 1992.L425en
dc.subject.lcshEndoplasmic reticulumen
dc.subject.lcshProteinsen
dc.subject.lcshSeeds -- Storageen
dc.subject.lcshZeinen
dc.titleStudy of zein protein body formation in a heterologous system (<i>Xenopus laevis oocyte</i>)en
dc.typeDissertationen
dc.type.dcmitypeTexten
thesis.degree.disciplineBiologyen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.leveldoctoralen
thesis.degree.namePh. D.en

Files

Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
LD5655.V856_1992.L425.pdf
Size:
7.03 MB
Format:
Adobe Portable Document Format
Download

Collections

Doctoral Dissertations