Mechanism for the selective conjugation of ubiquitin to phytochrome
The goal of this project is to understand at the molecular level how phytochrome functions and how intracellular proteins are degraded. Phytochrome is marked for degradation by covalent attachment of ubiquitin. Ubiquitin-phytochrome conjugates (UbP) were characterized with respect to formation kinetics, subcellular localization and site of ubiquitin attachment. UbP appears to be a general phenomenon during phytochrome degradation in a variety of species. UbP was isolated from oat seedlings and characterized. Residues 747-830 of phytochrome have been identified as a possible attachment site for ubiquitin. By placing the gene for etiolated phytochrome in tobacco we have created a transgenic system for over expressing phytochrome. The effects of this over expression are described, and it appears that tobacco degrades this foreign protein through formation of UbP. We have created a series of site-directed mutants of the oat phytochrome gene, and are in the process of characterizing them to determine sequence requirements for ubiquination. 8 refs., 1 fig. (MHB)
- Research Organization:
- Wisconsin Univ., Madison, WI (United States). Dept. of Horticulture
- Sponsoring Organization:
- DOE; USDOE, Washington, DC (United States)
- DOE Contract Number:
- FG02-88ER13968
- OSTI ID:
- 5229610
- Report Number(s):
- DOE/ER/13968-T3; ON: DE92000019
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
59 BASIC BIOLOGICAL SCIENCES
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL ACCUMULATION
BIOLOGICAL MODELS
BIOLOGICAL PATHWAYS
BIOTECHNOLOGY
CATABOLISM
CEREALS
CHEMICAL REACTIONS
DECOMPOSITION
DERIVATIZATION
DISTRIBUTION
DOCUMENT TYPES
GENE REGULATION
GENETIC ENGINEERING
GRAMINEAE
KINETICS
LILIOPSIDA
MAGNOLIOPHYTA
METABOLISM
MOLECULAR STRUCTURE
MORPHOLOGY
MUTAGENESIS
OATS
ORGANIC COMPOUNDS
PHYTOCHROMES
PIGMENTS
PLANTS
PROGRESS REPORT
PROTEINS
PROTEOLYSIS
REACTION INTERMEDIATES
REACTION KINETICS
SEEDLINGS
SUBCELLULAR DISTRIBUTION
TOBACCO