Related Experiment Videos
Partial characterization of GTP-binding proteins in Neurospora
Biochemical and Biophysical Research Communications
|August 14, 1987
Summary
Researchers identified six GTP-binding proteins in Neurospora crassa. These proteins bind GTP, are ADP-ribosylated by pertussis toxin, and exhibit varying affinities for GTP.
Area of Science:
- Molecular biology
- Biochemistry
- Mycology
Background:
- GTP-binding proteins are crucial regulators of cellular processes.
- Neurospora crassa is a model organism for studying fungal biology.
Purpose of the Study:
- To characterize GTP-binding proteins in Neurospora crassa.
- To investigate their binding properties and susceptibility to modification.
Main Methods:
- Gel filtration chromatography was used to separate protein fractions.
- [35S]GTP gamma S binding assays were performed.
- Competitive inhibition assays with GTP and ATP were conducted.
- ADP-ribosylation by pertussis toxin was assessed.
Main Results:
- Six distinct fractions of GTP-binding proteins were isolated.
- Binding was specific for GTP and inhibited by GTP, not ATP.
- Apparent Km values varied across the fractions (2-80 nM).
- All fractions were substrates for pertussis toxin-mediated ADP-ribosylation.
Conclusions:
- Neurospora crassa possesses multiple GTP-binding proteins with diverse kinetic properties.
- These proteins are likely involved in signal transduction pathways.
- Their susceptibility to pertussis toxin suggests potential roles in G protein-coupled pathways.