A 3' untranslated region of catalase mRNA composed of a stem-loop and dinucleotide repeat elements binds a 69-kDa redox-sensitive protein.
Rat lung extract contains protein that forms redox-sensitive, specific complexes with a 1130-base catalase cRNA (J. Biol. Chem. 267, 2853-2855, 1992). The present paper reports studies aimed at delimiting the site of protein binding on the RNA and characterizing the protein. A 240-base sequence was identified as the 3' untranslated region of catalase mRNA that binds lung protein in a redox-sensitive manner. Two elements within this 240-base region bind protein; one is a 36-base element that has a computer-predicted stem-loop secondary structure and the other is a CA dinucleotide repeat. Competition studies indicate that both elements are required for specific binding. Cross-competition experiments demonstrated that catalase RNA-binding protein (CAT-BP) is not the iron-responsive element-binding protein. Ultraviolet light-induced cross-linking and two-dimensional electrophoresis showed that CAT-BP has an apparent molecular mass of 69 kDa and appears to be composed of four isoforms. Competition studies indicate that stem-loop cis element is directly involved in binding CAT-BP. In addition to rat, the 69-kDa catalase RNA-binding protein is present in mouse and human fibroblast cell lines.
Clerch
L B
LB
Lung Biology Laboratory, Georgetown University Medical Center, Washington, DC 20007.
D000818:Animals; D001483:Base Sequence; D002374:Catalase / Q000378:metabolism*; D003198:Computer Simulation; D017124:Conserved Sequence; D008168:Lung / Q000378:metabolism*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010084:Oxidation-Reduction; D017433:Protein Structure, Secondary; D015347:RNA Probes; D012333:RNA, Messenger / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000378:metabolism*; D051381:Rats; D012091:Repetitive Sequences, Nucleic Acid
D015347:RNA Probes; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D002374:Catalase