Skip to main content
OSTI.GOVU.S. Department of Energy Office of Scientific and Technical Information
U.S. Department of Energy
Office of Scientific and Technical Information
 

ATP-dependent unwinding of messenger RNA structure by eukaryotic initiation factors

Journal Article · · J. Biol. Chem.; (United States)
OSTI ID:6432598
; ; ; ; ; ; ;
Interaction of protein synthesis initiation factors with mRNA has been studied in order to characterize early events in the eukaryotic translation pathway. Individual reovirus mRNAs labeled with /sup 32/P in the alpha position relative to the m7G cap and eukaryotic initiation factor (eIF)-4A, -4B, and -4F purified from rabbit reticulocytes were employed. It was found that eIF-4A causes a structural change in mRNA, as evidenced by a nuclease sensitivity test: addition of high concentrations of eIF-4A greatly increase the nuclease sensitivity of the mRNA, suggesting that this factor can melt or ''unwind'' mRNA structure. ATP is required for this reaction. At low concentrations of eIF-4A, addition of eIF-4B is required for maximal unwinding activity. Thus eIF-4B enhances eIF-4A activity. Addition of eIF-4F also makes the mRNA sensitive to nuclease indicating a similar unwinding role to that of eIF-4A. Stoichiometric comparisons indicate that eIF-4F is more than 20-fold more efficient than eIF-4A in catalyzing this reaction. The unwinding activity of eIF-4F is inhibited by m7GDP, while that of eIF-4A is not. This suggests that eIF-4A functions independent of the 5' cap structure. These results also suggest that the unwinding activity of eIF-4F is located in the 46,000-dalton polypeptide of this complex, which has shown by others to be similar or identical to eIF-4A.
OSTI ID:
6432598
Journal Information:
J. Biol. Chem.; (United States), Journal Name: J. Biol. Chem.; (United States) Vol. 12; ISSN JBCHA
Country of Publication:
United States
Language:
English

Similar Records

Dissociation of 5' proximal helical regions in messenger RNAs by eukaryotic initiation factors 4F, 4A, and 4B
Conference · Fri May 01 00:00:00 EDT 1987 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) · OSTI ID:6079238
Photoaffinity labeling of the cap-binding protein complex with ATP/dATP. Differential labeling of free eukaryotic initiation factor 4A and the eukaryotic initiation factor 4A component of the cap-binding protein complex with (alpha-TSP)ATP/dATP
Journal Article · Mon Nov 04 23:00:00 EST 1985 · J. Biol. Chem.; (United States) · OSTI ID:6086294
Evidence that eukaryotic initiation factor (eIF) 2 is a cap-binding protein that stimulates cap recognition by eIF-4B and eIF-4F
Journal Article · Mon Apr 15 00:00:00 EDT 1991 · Journal of Biological Chemistry; (USA) · OSTI ID:5761222

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMALS
ATP
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
DAYS LIVING RADIOISOTOPES
DNA
ENZYME ACTIVITY
ENZYMES
ERYTHROCYTES
ESTERASES
HYDROLASES
ISOTOPE APPLICATIONS
ISOTOPES
L CELLS
LIGHT NUCLEI
MAMMALS
MATERIALS
MESSENGER-RNA
MICE
MOLECULAR WEIGHT
NUCLEASES
NUCLEI
NUCLEIC ACIDS
NUCLEOTIDES
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
PHOSPHODIESTERASES
PHOSPHORUS 32
PHOSPHORUS ISOTOPES
PROTEINS
RABBITS
RADIOISOTOPES
RETICULOCYTES
RNA
RODENTS
STRUCTURE-ACTIVITY RELATIONSHIPS
TRACER TECHNIQUES
VERTEBRATES