Mark P. Sowden

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A functional mooring sequence, known to be required for apolipoprotein B (apoB) mRNA editing, exists in the mRNA encoding the neurofibromatosis type I (NF1) tumor suppressor. Editing of NF1 mRNA modifies cytidine in an arginine codon (CGA) at nucleotide 2914 to a uridine (UGA), creating an in frame translation stop codon. NF1 editing occurs in normal tissue(More)
RNA editing is a co- or post-transcriptional process in which select nucleotide sequences in RNA are altered from that originally encoded in the genome. The mRNAs encoding apolipoprotein B and some glutamate receptor subunits of ionotropic membrane channels are edited by site-specific base-deamination systems. Although these editing systems differ markedly(More)
Apolipoprotein B (apoB) mRNA editing is a nuclear event that minimally requires the RNA substrate, APOBEC-1 and APOBEC-1 Complementation Factor (ACF). The co-localization of these macro-molecules within the nucleus and the modulation of hepatic apoB mRNA editing activity have been described following a variety of metabolic perturbations, but the mechanism(More)
In mammals, activation-induced deaminase (AID) initiates somatic hypermutation (SHM) and class switch recombination (CSR) of Ig genes. SHM and CSR activities require separate regions within AID. A chromosome region maintenance 1 (CRM1)-dependent nuclear export signal (NES) at the AID C terminus is necessary for CSR, and has been suggested to associate with(More)
A variety of techniques are currently available for detecting point mutations in DNA. These techniques are frequently not sensitive enough to be applied as quantitative assays in evaluation of relative occurrence of alleles in cases of polymorphism or when variations in allelic gene expression are being evaluated at the level of RNA. We report here the(More)
The full-length gene product encoded by the E2 open reading frame (ORF) of bovine papillomavirus type 1 (BPV1) is a transcriptional transactivator. It is believed to mediate its effect on the BPV1 long control region (LCR) by binding to motifs with the consensus sequence ACCN6GGT. The minimal functional cis active site, called the E2 response element(More)
Transcription directed by the BPV-1 long control region (LCR) is conditional upon activation by the virally encoded E2 protein. Within the 1.0 kb LCR there are five separate regions, A to E, that contain E2 responsive enhancers. The smallest functional region, A, is only 38 bp and contains two copies of the consensus sequence ACC(N)6GGT that is known to(More)
Type 1 protein phosphataseretinoblastoma proteinserine/threonine dephosphorylationphosphatase activityinducible protein expression Abstract Background : One of the major cellular serine/threonine protein phosphatases is protein phosphatase type 1 (PP1). Studies employing many eukaryotic systems all point to a crucial role for PP1 activity in controlling(More)
Cytidine to uridine editing of apolipoprotein B (apoB) mRNA requires the cytidine deaminase APOBEC-1 as well as a tripartite sequence motif flanking a target cytidine in apoB mRNA and an undefined number of auxiliary proteins that mediate RNA recognition and determine site-specific editing. Yeast engineered to express APOBEC-1 and apoB mRNA supported(More)
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