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Redundant Genes (redundant + gene)

Distribution by Scientific Domains
Life Sciences80%

Selected Abstracts

Fibrate induction of the adrenoleukodystrophy-related gene (ABCD2)

FEBS JOURNAL, Issue 12 2001
Promoter analysis, role of the peroxisome proliferator-activated receptor PPAR
X-linked adrenoleukodystrophy (X-ALD) is a neurodegenerative disease due to a defect in the ABCD1 (ALD) gene. ABCD1, and the two close homologues ABCD2 (ALDR) and ABCD3 (PMP70), are genes encoding ATP-binding cassette half-transporters of the peroxisomal membrane. As overexpression of the ABCD2 or ABCD3 gene can reverse the biochemical phenotype of X-ALD (reduced ,-oxidation of very-long-chain fatty acids), pharmacological induction of these partially redundant genes may represent a therapeutic approach to X-ALD. We previously reported that the ABCD2 and ABCD3 genes could be strongly induced by fibrates, which are hypolipidaemic drugs and peroxisome-proliferators in rodents. We provide evidence that the induction is dependent on peroxisome proliferator-activated receptor (PPAR,) as both genes were not induced in fenofibrate-treated PPAR,,/, knock-out mice. To further characterize the PPAR, pathway, we cloned and analysed the promoter of the ABCD2 gene, the closest homologue of the ABCD1 gene. The proximal region (2 kb) of the rat promoter displayed a high conservation with the human and mouse cognate sequences suggesting an important role of the region in regulation of the ABCD2 gene. Classically, fibrate-induction involves interaction of PPAR, with a response element (PPRE) characterized by a direct repeat of the AGGTCA-like motif. Putative PPRE motifs of the rat ABCD2 promoter were studied in the isolated form or in their promoter context by gel-shift assay and transfection of COS-7 cells. We failed to characterize a functional PPRE, suggesting a different mechanism for the PPAR,-dependent regulation of the ABCD2 gene. [source]

Chemotaxis in Vibrio cholerae

FEMS MICROBIOLOGY LETTERS, Issue 1 2004
Markus A. Boin
Abstract The ability of motile bacteria to swim toward or away from specific environmental stimuli, such as nutrients, oxygen, or light provides cells with a survival advantage, especially under nutrient-limiting conditions. This behavior, called chemotaxis, is mediated by the bacteria changing direction by briefly reversing the direction of rotation of the flagellar motors. A sophisticated signal transduction system, consisting of signal transducer proteins, a histidine kinase, a response regulator, a coupling protein, and enzymes that mediate sensory adaptation, relates the input signal to the flagellar motor. Chemotaxis has been extensively studied in bacteria such as Escherichia coli and Salmonella enterica serovar Typhimurium, and depends on the activity of single copies of proteins in a linear pathway. However, growing evidence suggests that chemotaxis in other bacteria is more complex with many bacterial species having multiple paralogues of the various chemotaxis genes found in E. coli and, in most cases, the detailed functions of these potentially redundant genes have not been elucidated. Although the completed genome of Vibrio cholerae, the causative agent of cholera, predicted a multitude of genes with homology to known chemotaxis-related genes, little is known about their relative contribution to chemotaxis or other cellular functions. Furthermore, the role of chemotaxis during the environmental or infectious phases of this organism is not yet fully understood. This review will focus on the complex relationship between chemotaxis and virulence in V. cholerae. [source]

MINIREVIEW: On the use of metaphor to understand, explain, or rationalize redundant genes in yeast

FEMS YEAST RESEARCH, Issue 3 2008
Stephen Cooper
Abstract The proposal that yeast, and cells in general, contains redundant genes that enable cells to survive mutational change has been supported by experiments and a strong metaphor. The redundant gene proposal is analyzed, and it is noted that there are many problems with the redundant gene model. An alternative metaphor is suggested to explain the genetic composition of a yeast culture. [source]

SHORT COMMUNICATION: Response to Dr Stephen Cooper's ,On the use of metaphor to understand, explain, or rationalize redundant genes in yeast'

FEMS YEAST RESEARCH, Issue 3 2008
Xuewen Pan
Abstract Earlier use of a metaphor in explaining genetic redundancy in a news article has triggered a commentary and a competing metaphor by Dr Stephen Cooper, who went on to conclude that genetic redundancies are relatively unimportant for microorganisms. We argue here that the new metaphor is flawed and that genetic redundancies are integral to buffering all organisms against environmental and genetic damage. [source]