The tetracycline (tet)-regulated expression system allows for the inducible overexpression of protein-coding genes, or inducible gene knockdown based on expression of short hairpin RNAs (shRNAs). The system is widely used in mice, however it requires robust expression of a tet transactivator protein (tTA or rtTA) in the cell type of interest. Here we used an in vivo tet-regulated fluorescent re...

Tetracycline resistance protein Tet(O), which protects the bacterial ribosome from binding the antibiotic tetracycline, is a translational GTPase with significant similarity in both sequence and structure to the elongation factor EF-G. Here, we present an atomic model of the Tet(O)-bound 70S ribosome based on our cryo-electron microscopic reconstruction at 9.6-Å resolution. This atomic model al...

The widespread use of antibiotics for medical and veterinary purposes has led to an increase of microbial resistance. The antibiotic resistance of pathogenic bacteria has been studied extensively. However, antibiotics are not only selective for pathogens: they also affect all members of the gut microbiota. These microorganisms may constitute a reservoir of genes carrying resistance to specific ...

The abundance of six tetracycline resistance genes tet(O), tet(Q), tet(W), tet(M), tet(B) and tet(L), were quantified over time in wastewater lagoons at concentrated animal feeding operations (CAFO) to assess how feedlot operation affects resistance genes in downstream surface waters. Eight lagoons at five cattle feedlots in the Midwestern United States were monitored for 6 months. Resistance a...

Tetracycline-resistant Pasteurella aerogenes isolates obtained from the intestinal tract of swine were investigated for their tet genes by PCR analysis and hybridization experiments. In contrast to Pasteurella isolates from the respiratory tract, tet(H) genes were detected in the chromosomal DNA of only 2 of the 24 isolates, one of which also carried two copies of a tet(B) gene. All other P. ae...

Tigecycline, the latest member of the tetracycline family to enter clinics, is reported to be poorly recognized by the most prevalent Gram-negative tetracycline-specific efflux mechanisms, namely, the Tet(A) and Tet(B) efflux pumps (1). These structurally related tetracycline-specific efflux pumps are encoded by genes on plasmids and transposons in a wide variety of bacteria and are proton-driv...

The tetracycline (TET) promoter has been used in several systems as an inducible regulator of gene expression. In control analyses, the standard Candida albicans laboratory strain SC5314 was found to have altered susceptibility to a variety of antifungal drugs in the presence of relatively high concentrations (50-200 microg ml(-1)) of TET. Altered susceptibility was most notable with exposure t...

DNA methylation at the fifth position of cytosine (5mC) is an important epigenetic modification that affects chromatin structure and gene expression. Recent studies have established a critical function of the Ten-eleven translocation (Tet) family of proteins in regulating DNA methylation dynamics. Three Tet genes have been identified in mammals, and they all encode for proteins capable of oxidi...

BACKGROUND Tetrandrine, a bisbenzylisoquinoline alkaloid, has cancer cell cytotoxicity. The effects of combined tetrandrine and radiation, alone or combined, on human SH-SY5Y neuroblastoma cells were examined. MATERIALS AND METHODS A combination treatment, using either concomitant irradiation at the beginning or end of the tetrandrine treatment (designated as the RT-Tet and Tet-RT protocols, ...