Identification of a rice RNA- and microtubule-binding protein as the multifunctional protein, a peroxisomal enzyme involved in the beta -oxidation of fatty acids.
The control of subcellular mRNA localization and translation is often mediated by protein factors that are directly or indirectly associated with the cytoskeleton. We report the identification and characterization of a rice seed protein that possesses both RNA and microtubule binding activities. In vitro UV cross-linking assays indicated that this protein binds to all mRNA sequences tested, although there was evidence for preferential binding to RNAs that contained A-C nucleotide sequence motifs. The protein was purified to homogeneity using a two-step procedure, and amino acid sequencing identified it as the multifunctional protein (MFP), a peroxisomal enzyme known to possess a number of activities involved in the beta-oxidation of fatty acids. The recombinant version of this rice MFP binds to RNA in UV cross-linking and gel mobility shift experiments, co-sediments specifically with microtubules, and possesses at least two enzymatic activities involved in peroxisomal fatty acid beta-oxidation. Taken together these data suggest that MFP has an important role in mRNA physiology in the cytoplasm, perhaps in regulating the localization or translation of mRNAs through an interaction with microtubules, in addition to its peroxisomal function.
Chuong
Simon D X
SD
Department of Biological Sciences, University of Calgary, Calgary, Alberta T2N 1N4, Canada.
Mullen
Robert T
RT
Muench
Douglas G
DG
D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D002846:Chromatography, Affinity; D003432:Cross-Linking Reagents / Q000494:pharmacology; D003593:Cytoplasm / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D020224:Expressed Sequence Tags; D005227:Fatty Acids / Q000378:metabolism*; D007700:Kinetics; D008870:Microtubules / Q000378:metabolism; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000737:chemistry* / Q000235:genetics*; D012275:Oryza / Q000737:chemistry*; D010100:Oxygen / Q000378:metabolism*; D020675:Peroxisomes / Q000201:enzymology*; D010940:Plant Proteins; D011189:Potassium Chloride / Q000494:pharmacology; D011485:Protein Binding; D012313:RNA / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D014404:Tubulin / Q000378:metabolism; D014466:Ultraviolet Rays
D003432:Cross-Linking Reagents; D005227:Fatty Acids; D009097:Multienzyme Complexes; D010940:Plant Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D011994:Recombinant Proteins; D014404:Tubulin; C447611:peroxisomal multifunctional protein, Oryza sativa; D012313:RNA; D011189:Potassium Chloride; D010100:Oxygen