A cytidine deaminase expressed in the post-infective L3 stage of the filarial nematode, Brugia pahangi, has a novel RNA-binding activity

Anant, S., Martin, S. A.M., Yu, H., MacGinnitie, A. J., Devaney, E. and Davidson, N. O. (1997) A cytidine deaminase expressed in the post-infective L3 stage of the filarial nematode, Brugia pahangi, has a novel RNA-binding activity. Molecular and Biochemical Parasitology, 88(1-2), pp. 105-114. (doi: 10.1016/S0166-6851(97)00083-2) (PMID:9274872)

Abstract

A number of genes have been identified that are highly expressed in the post-infective L3 stage of the filarial parasite, Brugia pahangi. Amongst these was a cDNA with homology to the cytidine deaminase (CDD) gene family. Phylogenetic analysis of the various cytosine nucleoside deaminases suggest that Brugia pahangi CDD evolved with significant divergence from the RNA editing family. In order to characterize its function, we have expressed Brugia pahangi CDD in bacteria as a chimera with maltose-binding protein (MBP). Biochemical analysis demonstrates the MBP-CDD fusion protein functions as an authentic cytidine deaminase with an obligate requirement for zinc. In addition to cytidine deaminase activity, however, the fusion protein demonstrates RNA binding activity with specificity for AU-rich sequences and was found to bind an RNA template spanning the edited site of mammalian apolipoprotein B (apoB) mRNA. This RNA binding activity was not found in two different recombinant bacterial CDD proteins. In vitro RNA editing assays revealed that MBP-CDD failed to mediate cytidine deamination of a mammalian apoB RNA template. Furthermore, binding of MBP-CDD to the apoB RNA did not inhibit in vitro editing of this template by apobec-1. The data suggest that the cytosine nucleoside deaminases and RNA editing deaminases have acquired different mechanisms of binding to an AU-rich RNA template, presumably with different functional implications.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Devaney, Professor Eileen
• Authors: Anant, S., Martin, S. A.M., Yu, H., MacGinnitie, A. J., Devaney, E., and Davidson, N. O.
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: Molecular and Biochemical Parasitology
• Publisher: Elsevier BV
• ISSN: 0166-6851
• ISSN (Online): 1872-9428|
• Published Online: 28 August 1998