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Author Abell, B. M. ♦ Holbrook, L. A. ♦ Abenes, M. ♦ Murphy, D. J. ♦ Hills, M. J. ♦ Moloney, M. M.
Source World Health Organization (WHO)-Global Index Medicus
Content type Text
Publisher American Society of Plant Biologists
File Format HTM / HTML
Language English
Difficulty Level Medium
Subject Domain (in DDC) Computer science, information & general works ♦ Library & information sciences ♦ Natural sciences & mathematics ♦ Chemistry & allied sciences ♦ Life sciences; biology ♦ Physiology & related subjects ♦ Biochemistry ♦ Genetics and evolution ♦ Natural history of organisms ♦ Technology ♦ Medicine & health ♦ Human anatomy, cytology, histology ♦ Human physiology ♦ Pharmacology and therapeutics ♦ Diseases ♦ Manufacture for specific uses ♦ Precision instruments & other devices
Subject Domain (in MeSH) Cells ♦ Anatomy ♦ Eukaryota ♦ Organisms ♦ Lipids ♦ Amino Acids, Peptides, and Proteins ♦ Nucleic Acids, Nucleotides, and Nucleosides ♦ Chemicals and Drugs ♦ Investigative Techniques ♦ Analytical, Diagnostic and Therapeutic Techniques and Equipment ♦ Chemical Phenomena ♦ Genetic Phenomena ♦ Biological Sciences ♦ Information Science ♦ Information Science
Subject Keyword Discipline Botany ♦ Arabidopsis Proteins ♦ Arabidopsis ♦ Metabolism ♦ Plant Proteins ♦ Chemistry ♦ Amino Acid Sequence ♦ Animals ♦ Genetics ♦ Ultrastructure ♦ Base Sequence ♦ Dna Primers ♦ Dna, Plant ♦ Dogs ♦ Endoplasmic Reticulum ♦ Genetic Variation ♦ In Vitro Techniques ♦ Inclusion Bodies ♦ Membrane Proteins ♦ Microsomes ♦ Molecular Sequence Data ♦ Plant Oils ♦ Plants, Genetically Modified ♦ Proline ♦ Protein Biosynthesis ♦ Protein Conformation ♦ Rna, Messenger ♦ Recombinant Fusion Proteins ♦ Soybeans ♦ Journal Article ♦ Research Support, Non-u.s. Gov't
Abstract An Arabidopsis oleosin was used as a model to study oleosin topology and targeting to oil bodies. Oleosin mRNA was in vitro translated with canine microsomes in a range of truncated forms. This allowed proteinase K mapping of the membrane topology. Oleosin maintains a conformation with a membrane-integrated hydrophobic domain flanked by N- and C-terminal domains located on the outer microsome surface. This is a unique membrane topology on the endoplasmic reticulum (ER). Three universally conserved proline residues within the 'proline knot' motif of the oleosin hydrophobic domain were substituted by leucine residues. After in vitro translation, only minor differences in proteinase K protection could be observed. These differences were not apparent in soybean microsomes. No significant difference in incorporation efficiency on the ER was observed between the two oleosin forms. However, as an oleosin-beta-glucuronidase translational fusion, the proline knot variant failed to target to oil bodies in both transient embryo expression and in stably transformed seeds. Fractionation of transgenic embryos expressing oleosin-beta-glucuronidase fusions showed that the proline knot variant accumulated in the ER to similar levels compared with the native form. Therefore, the proline knot motif is not important for ER integration and the determination of topology but is required for oil body targeting. The loss of the proline knot results in an intrinsic instability in the oleosin polypeptide during trafficking.
Description Country affiliation: Canada
Author Affiliation: Abell BM ( Department of Biological Sciences, University of Calgary, Alberta, Canada.)
ISSN 10404651
Educational Role Student ♦ Teacher
Age Range above 22 year
Educational Use Reading ♦ Research ♦ Self Learning
Interactivity Type Expositive
Education Level UG and PG
Learning Resource Type Article
Publisher Date 1997-08-01
Publisher Place United States
e-ISSN 1531298X
Volume Number 9
Issue Number 8

Source: WHO-Global Index Medicus