MCB
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Mehta, A.
Right arrow Articles by Driscoll, D. M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Mehta, A.
Right arrow Articles by Driscoll, D. M.

 Previous Article  |  Next Article 

Molecular and Cellular Biology, March 2000, p. 1846-1854, Vol. 20, No. 5
0270-7306/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.

Molecular Cloning of Apobec-1 Complementation Factor, a Novel RNA-Binding Protein Involved in the Editing of Apolipoprotein B mRNA

Anuradha Mehta,1 Michael T. Kinter,2,dagger Nicholas E. Sherman,2 and Donna M. Driscoll1,*

Department of Cell Biology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio 44195,1 and W. M. Keck Biomedical Mass Spectrometry Laboratory, Department of Microbiology, University of Virginia, Charlottesville, Virginia 229082

Received 21 October 1999/Returned for modification 27 November 1999/Accepted 1 December 1999

The C-to-U editing of apolipoprotein B (apo-B) mRNA is catalyzed by a multiprotein complex that recognizes an 11-nucleotide mooring sequence downstream of the editing site. The catalytic subunit of the editing enzyme, apobec-1, has cytidine deaminase activity but requires additional unidentified proteins to edit apo-B mRNA. We purified a 65-kDa protein that functionally complements apobec-1 and obtained peptide sequence information which was used in molecular cloning experiments. The apobec-1 complementation factor (ACF) cDNA encodes a novel 64.3-kDa protein that contains three nonidentical RNA recognition motifs. ACF and apobec-1 comprise the minimal protein requirements for apo-B mRNA editing in vitro. By UV cross-linking and immunoprecipitation, we show that ACF binds to apo-B mRNA in vitro and in vivo. Cross-linking of ACF is not competed by RNAs with mutations in the mooring sequence. Coimmunoprecipitation experiments identified an ACF-apobec-1 complex in transfected cells. Immunodepletion of ACF from rat liver extracts abolished editing activity. The immunoprecipitated complexes contained a functional holoenzyme. Our results support a model of the editing enzyme in which ACF binds to the mooring sequence in apo-B mRNA and docks apobec-1 to deaminate its target cytidine. The fact that ACF is widely expressed in human tissues that lack apobec-1 and apo-B mRNA suggests that ACF may be involved in other RNA editing or RNA processing events.

* Corresponding author. Mailing address: Department of Cell Biology, Lerner Research Institute, Cleveland Clinic Foundation, 9500 Euclid Ave. #NC-10, Cleveland, OH 44195. Phone: (216) 445-9758. Fax: (216) 444-9404. E-mail: driscod{at}ccf.org.

dagger Present address: Department of Cell Biology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195.

Molecular and Cellular Biology, March 2000, p. 1846-1854, Vol. 20, No. 5
0270-7306/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. J. Virol. Eukaryot. Cell
Microbiol. Mol. Biol. Rev. Clin. Vaccine Immunol. All ASM Journals

Copyright © 2000 by the American Society for Microbiology. All rights reserved.