Gary Foster - Academia.edu (original) (raw)

Papers by Gary Foster

Research paper thumbnail of Maturation-specific translational enhancement mediated by the 5'-UTR of a late pollen transcript

Plant Journal, 1996

The tomato lat52 gene encodes an abundant protein specifically expressed in the vegetative cell o... more The tomato lat52 gene encodes an abundant protein specifically expressed in the vegetative cell of the pollen grain during pollen maturation which is essential for normal pollen tube growth. Multiple upstream cis-regulatory elements controlling the level and specificity of lat52 transcription have previously been identified. This research investigated the role of the 5′-untranslated region (5′-UTR) in controlling lat52 expression. In transient expression assays, gene fusion constructs containing the lat52 5′-UTR were expressed in pollen at levels 13- to 60-fold above those in which synthetic polylinker sequences replaced the lat52 5′-UTR. This enhancement was shown to be independent of both the promoter sequences, the linked reporter gene and the 3′-UTR. Analysis of RNA and protein levels in transgenic plants containing such gene fusions demonstrated that the lat52 5′-UTR conferred a dramatically increased translational yield to heterologous transcripts in a pollen-specific and strictly developmentally regulated manner during the final stages of pollen maturation. These results represent a novel example of translational enhancement in plants in that translational yield is regulated developmentally in a cell-specific manner via sequences located within the 5′-UTR.

Research paper thumbnail of Analysis of a translational enhancer upstream from the coat protein open reading frame of potato virus S

Archives of Virology, 1994

Evidence has suggested that the subgenomic RNA of the carlavirus potato virus S is an efficient m... more Evidence has suggested that the subgenomic RNA of the carlavirus potato virus S is an efficient message for the coat protein, even though evidence suggests it is uncapped at its 5' terminus. We have investigated the effect of the upstream region of the coat protein gene of potato virus S on the level of reporter gene expression in vitro. The region of 101 nucleotides upstream of the coat protein, designated VTE (viral translational enhancer) was found to increase levels of translation in comparison to a synthetic leader when linked to the beta-glucuronidase (GUS) reporter gene in vitro in rabbit reticulocyte and wheat germ lysate. VTE was also able to increase translation of the reporter gene luciferase (LUC) in vitro above the levels obtained for both a synthetic leader and a leader obtained from a plant gene isolated from Arabidopsis thaliana. The level of enhancement was evident with both capped and uncapped transcripts. When the VTE sequence was deleted to 20 nucleotides of the upstream region, thus removing the nucleotide block homologous among carlaviruses, the ability to enhance levels of translation was removed. In vitro translation studies indicated that the translational enhancement activity of VTE was at least partially cap independent. Translation of VTE linked to reporter genes in the presence of cap analogue was relatively unaffected whereas synthetic leader and a plant leader constructs were both more sensitive. In vitro competition analysis revealed that when short RNA transcripts representing the 101 nucleotides of VTE were added in trans to functional VTE leader LUC constructs there was a marked decrease in the level of translation when compared with a synthetic leader added in trans. These results suggest that the upstream region of the coat protein ORF of potato virus S promotes translation in a cap-independent manner that may involve the binding of proteins and/or ribosomes to the 101 nucleotides of the VTE sequence.

Research paper thumbnail of Analysis of a translational enhancer present within the 5′-terminal sequence of the genomic RNA of potato virus S

Archives of Virology, 1999

When present as a transcript leader the 5 untranslated sequence from the potato virus S genomic R... more When present as a transcript leader the 5 untranslated sequence from the potato virus S genomic RNA molecule enhances translation of a downstream open reading frame both in vitro and in vivo. Translational enhancement was 30fold in rabbit reticulocyte lysate and 15 fold in wheat germ above translation from a transcript with a synthetic leader. Transient expression experiments using tobacco protoplasts and particle bombardment of leaf tissue resulted in enhancement of fourteen and five-fold, respectively, above translation with a synthetic leader. In stably transformed plants the PVS 5 UTR enhanced translation yield ca. 5-fold compared with a synthetic 5 UTR. * Viruses have employed ingenious mechanisms to achieve the maximum rate of multiplication and spread throughout their hosts. The regulation of translation has been exploited to achieve efficient viral protein synthesis. One important factor affecting translational competence is the nature of the 5 untranslated leader (UTR) sequence of the mRNA. Translational enhancement conferred by the 5 UTR of viral positive-sense, single-stranded RNA genomes has been documented for members of many plant viral genera [1]. Examples of plant viral translational enhancers have included the potyviruses tobacco etch virus (TEV) [2] and pea seed borne mosaic virus (PSbMV) [3], the tobamovirus tobacco mosaic virus (TMV) [4, 5], and the satellite RNA of tobacco necrosis virus (TNV) [6] among

Research paper thumbnail of In vivo characterisation of a translational enhancer upstream from the coat protein open reading frame of potato virus S

Archives of Virology, 1994

The 101 nucleotide region upstream from the ATG of the potato virus S (PVS) coat protein gene was... more The 101 nucleotide region upstream from the ATG of the potato virus S (PVS) coat protein gene was isolated and the effect of this region on the translation of a downstream open reading frame analysed in vivo. Translation was monitored using the reporter genes B-glucuronidase (GUS) and luciferase (LUC). Translational enhancement was assayed transiently using DNA microprojectile bombardment into both leaf and pollen tissue and also by polyethylene glycol mediated transfection of tobacco protoplasts. In both cases the presence of this region resulted in a 2-3 fold increase in translation when compared to reporter expression with synthetic leader and authentic plant leader constructs. Tobacco plants stabily transformed with this PVS 101 nucleotide region and downstream GUS gene gave 4 times the level of translation over synthetic leader GUS control plants.

Research paper thumbnail of Efficient GFP expression in the mushrooms Agaricus bisporus and Coprinus cinereus requires introns

Fungal Genetics and Biology, 2005

We have developed a "Molecular Toolkit" comprising interchangeable promoters and marker genes to ... more We have developed a "Molecular Toolkit" comprising interchangeable promoters and marker genes to facilitate transformation of homobasidiomycete mushrooms. We describe the evaluation of a range of promoters in the homobasidiomycetes Agaricus bisporus and Coprinus cinereus using green Xuorescent protein (GFP) as a reporter gene; the C. cinereus trp1 promoter and A. bisporus trp2 and gpdII promoters proving successful in driving expression in C. cinereus, with the gpdII promoter also functioning in A. bisporus. Our investigations demonstrate that a prerequisite for GFP expression in C. cinereus and A. bisporus is the presence of an intron. This is the Wrst reported expression of GFP in either C. cinereus or A. bisporus.

Research paper thumbnail of Maturation-specific translational enhancement mediated by the 5'-UTR of a late pollen transcript

Plant Journal, 1996

The tomato lat52 gene encodes an abundant protein specifically expressed in the vegetative cell o... more The tomato lat52 gene encodes an abundant protein specifically expressed in the vegetative cell of the pollen grain during pollen maturation which is essential for normal pollen tube growth. Multiple upstream cis-regulatory elements controlling the level and specificity of lat52 transcription have previously been identified. This research investigated the role of the 5′-untranslated region (5′-UTR) in controlling lat52 expression. In transient expression assays, gene fusion constructs containing the lat52 5′-UTR were expressed in pollen at levels 13- to 60-fold above those in which synthetic polylinker sequences replaced the lat52 5′-UTR. This enhancement was shown to be independent of both the promoter sequences, the linked reporter gene and the 3′-UTR. Analysis of RNA and protein levels in transgenic plants containing such gene fusions demonstrated that the lat52 5′-UTR conferred a dramatically increased translational yield to heterologous transcripts in a pollen-specific and strictly developmentally regulated manner during the final stages of pollen maturation. These results represent a novel example of translational enhancement in plants in that translational yield is regulated developmentally in a cell-specific manner via sequences located within the 5′-UTR.

Research paper thumbnail of Analysis of a translational enhancer upstream from the coat protein open reading frame of potato virus S

Archives of Virology, 1994

Evidence has suggested that the subgenomic RNA of the carlavirus potato virus S is an efficient m... more Evidence has suggested that the subgenomic RNA of the carlavirus potato virus S is an efficient message for the coat protein, even though evidence suggests it is uncapped at its 5' terminus. We have investigated the effect of the upstream region of the coat protein gene of potato virus S on the level of reporter gene expression in vitro. The region of 101 nucleotides upstream of the coat protein, designated VTE (viral translational enhancer) was found to increase levels of translation in comparison to a synthetic leader when linked to the beta-glucuronidase (GUS) reporter gene in vitro in rabbit reticulocyte and wheat germ lysate. VTE was also able to increase translation of the reporter gene luciferase (LUC) in vitro above the levels obtained for both a synthetic leader and a leader obtained from a plant gene isolated from Arabidopsis thaliana. The level of enhancement was evident with both capped and uncapped transcripts. When the VTE sequence was deleted to 20 nucleotides of the upstream region, thus removing the nucleotide block homologous among carlaviruses, the ability to enhance levels of translation was removed. In vitro translation studies indicated that the translational enhancement activity of VTE was at least partially cap independent. Translation of VTE linked to reporter genes in the presence of cap analogue was relatively unaffected whereas synthetic leader and a plant leader constructs were both more sensitive. In vitro competition analysis revealed that when short RNA transcripts representing the 101 nucleotides of VTE were added in trans to functional VTE leader LUC constructs there was a marked decrease in the level of translation when compared with a synthetic leader added in trans. These results suggest that the upstream region of the coat protein ORF of potato virus S promotes translation in a cap-independent manner that may involve the binding of proteins and/or ribosomes to the 101 nucleotides of the VTE sequence.

Research paper thumbnail of Analysis of a translational enhancer present within the 5′-terminal sequence of the genomic RNA of potato virus S

Archives of Virology, 1999

When present as a transcript leader the 5 untranslated sequence from the potato virus S genomic R... more When present as a transcript leader the 5 untranslated sequence from the potato virus S genomic RNA molecule enhances translation of a downstream open reading frame both in vitro and in vivo. Translational enhancement was 30fold in rabbit reticulocyte lysate and 15 fold in wheat germ above translation from a transcript with a synthetic leader. Transient expression experiments using tobacco protoplasts and particle bombardment of leaf tissue resulted in enhancement of fourteen and five-fold, respectively, above translation with a synthetic leader. In stably transformed plants the PVS 5 UTR enhanced translation yield ca. 5-fold compared with a synthetic 5 UTR. * Viruses have employed ingenious mechanisms to achieve the maximum rate of multiplication and spread throughout their hosts. The regulation of translation has been exploited to achieve efficient viral protein synthesis. One important factor affecting translational competence is the nature of the 5 untranslated leader (UTR) sequence of the mRNA. Translational enhancement conferred by the 5 UTR of viral positive-sense, single-stranded RNA genomes has been documented for members of many plant viral genera [1]. Examples of plant viral translational enhancers have included the potyviruses tobacco etch virus (TEV) [2] and pea seed borne mosaic virus (PSbMV) [3], the tobamovirus tobacco mosaic virus (TMV) [4, 5], and the satellite RNA of tobacco necrosis virus (TNV) [6] among

Research paper thumbnail of In vivo characterisation of a translational enhancer upstream from the coat protein open reading frame of potato virus S

Archives of Virology, 1994

The 101 nucleotide region upstream from the ATG of the potato virus S (PVS) coat protein gene was... more The 101 nucleotide region upstream from the ATG of the potato virus S (PVS) coat protein gene was isolated and the effect of this region on the translation of a downstream open reading frame analysed in vivo. Translation was monitored using the reporter genes B-glucuronidase (GUS) and luciferase (LUC). Translational enhancement was assayed transiently using DNA microprojectile bombardment into both leaf and pollen tissue and also by polyethylene glycol mediated transfection of tobacco protoplasts. In both cases the presence of this region resulted in a 2-3 fold increase in translation when compared to reporter expression with synthetic leader and authentic plant leader constructs. Tobacco plants stabily transformed with this PVS 101 nucleotide region and downstream GUS gene gave 4 times the level of translation over synthetic leader GUS control plants.

Research paper thumbnail of Efficient GFP expression in the mushrooms Agaricus bisporus and Coprinus cinereus requires introns

Fungal Genetics and Biology, 2005

We have developed a "Molecular Toolkit" comprising interchangeable promoters and marker genes to ... more We have developed a "Molecular Toolkit" comprising interchangeable promoters and marker genes to facilitate transformation of homobasidiomycete mushrooms. We describe the evaluation of a range of promoters in the homobasidiomycetes Agaricus bisporus and Coprinus cinereus using green Xuorescent protein (GFP) as a reporter gene; the C. cinereus trp1 promoter and A. bisporus trp2 and gpdII promoters proving successful in driving expression in C. cinereus, with the gpdII promoter also functioning in A. bisporus. Our investigations demonstrate that a prerequisite for GFP expression in C. cinereus and A. bisporus is the presence of an intron. This is the Wrst reported expression of GFP in either C. cinereus or A. bisporus.