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Glial fibrillary acidic protein (GFAP) is an intermediate-filament (IF) protein that is highly specific for cells of astroglial lineage, although its tissue-specific role is speculative. Determination of the primary structure of this protein should be of importance for understanding the functional role it plays in astroglia. Therefore, we isolated a cDNA(More)
Shigella flexneri possesses multiple iron acquisition systems, including proteins involved in the synthesis and uptake of siderophores and the Feo system for ferrous iron utilization. We identified an additional S. flexneri putative iron transport gene, sitA, in a screen for S. flexneri genes that are induced in the eukaryotic intracellular environment.(More)
The control of cell cycle progression is orchestrated by an extraordinary diverse and dynamic in function group of proteins. Critical in the progression are the actions of the E2F family of transcription factors which regulate the expression of genes necessary for the G1/S transition and the WAF/CIP/KIP family of cdk inhibitors which can inhibit cell cycle(More)
Genes encoding the synthesis and transport of aerobactin, a hydroxamate siderophore associated with increased virulence of enteric bacteria, were mapped within a pathogenicity island in Shigella flexneri. The island, designated SHI-2 for Shigella pathogenicity island 2, was located downstream of selC, the site of insertion of pathogenicity islands in(More)
The rate of electron transfer through multicomponent redox systems is often monitored by following the absorbance change due to the oxidation of the upstream pyridine nucleotide electron donor (NADPH or NADH) that initiates the process. Such coupled assay systems are powerful, but because of problems regarding the rate-limiting step, they sometimes limit(More)
To assess the importance of TonB-dependent iron transport systems to growth of Shigella in vivo, a tonB mutant of Shigella dysenteriae was isolated and tested in cultured cells. The tonB mutant invaded epithelial cells, but did not form plaques in confluent monolayers of Henle cells, indicating an inability of this mutant to spread from cell to cell. The(More)
In Escherichia coli, bacterioferritin comigratory protein (BCP) is a peroxiredoxin (Prx) that catalyzes the reduction of H(2)O(2) and organic hydroperoxides. This protein, along with plant PrxQ, is a founding member of one of the least studied subfamilies of Prxs. Recent structural data have suggested that proteins in the BCP/PrxQ group can exist as(More)
Cyclin D1 plays a key regulatory role during the G1 phase of the cell cycle and its gene is amplified and overexpressed in many cancers. To address the relationship between cyclin D1 and other cell cycle regulatory proteins, we established human glioma and rodent fibroblast cell lines in which cyclin D1 expression could be regulated ectopically with(More)
DNA damaging agents such as ultraviolet (UV) induce cell cycle arrest followed by apoptosis in cells where irreparable damage has occurred. Here we show that during early phase G1 arrest which occurs in UV-irradiated human U343 glioblastoma cells, there are (1) decreases in cyclin D1 and cdk4 levels which parallel a loss of S-phase promoting cyclin D1/cdk4(More)
A variety of growth factors including transforming growth factor-alpha (TGF-alpha) are synthesized as transmembrane precursors. The short cytoplasmic domain of the transmembrane TGF-alpha precursor lacks any apparent motif associated with signal transduction. However, the sequence conservation of this cytoplasmic domain and its abundance of cysteine(More)