Registered users receive a variety of benefits including the ability to customize email alerts, create favorite journals list, and save searches.
Please note that a BioOne web account does not automatically grant access to full-text content. An institutional or society member subscription is required to view non-Open Access content.
Contact firstname.lastname@example.org with any questions.
NF-κB is an evolutionarily conserved eukaryotic transcription factor that plays a role in many important developmental and immune-related processes by activating target gene expression. The goal of these experiments was to define the sequences required for a sea anemone NF-κB's intrinsic transactivation activity by using mutant proteins with serial deletions of the N- and C-terminal sequences. Deletion mutants were constructed that were missing the C-terminal 15, 32 or 47 amino acids (aa) or the N-terminal 17, 27 or 47 aa of the 440 aa NF-κB protein from the starlet sea anemone, Nematostella vectensis (Nv), a simple model organism in the phylum Cnidaria. These Nv-NF-κB mutants were expressed as GAL4 fusion proteins in yeast, and their transactivation activities were assessed by LacZ reporter gene assays. The deletion of 47 aa from either the N terminus or the C terminus of NF-κB completely inactivates the transactivation function of Nv-NF-κB. In addition, we identified proline-258 in the center of the protein as a key residue for the transactivation function of Nv-NF-κB. Taken together, these results demonstrate that non-conserved N- and C-terminal residues are both required for the transcriptional activating function of the sea anemone NF-κB protein, suggesting that it has a novel functional domain structure among known NF-κB proteins.
The long coevolution of β-herpesviruses with humans has resulted in the acquisition of a large variety of immune evasion strategies by these viruses. Presumably immune evasion genes are necessary for each herpesvirus to establish a life-long infection in their host. Human herpesvirus 7 (HHV-7) is a relatively understudied virus, likely because it does not typically pose significant health concerns. HHV-7 establishes a life-long infection in approximately 90% of the population before the age of 3 suggesting it likely possesses significant immune evasion strategies. Several genes found in a cluster near a known immune evasion gene, U21, may possibly encode novel immune evasion proteins. In an attempt to determine the function of one of these genes, U20, we previously expressed the protein in a variety of cell types. As predicted, U20 is a type I membrane protein targeted to the secretory system through a predicted N-terminal signal sequence. Interestingly, although U20 does not possess any predicted endoplasmic reticulum (ER) retention motifs, the exogenously expressed protein remained localized to the ER in all cell types examined. Here we describe a cloning project to generate constructs that will be used to examine the role of each domain (lumenal, transmembrane, or cytoplasmic) of U20 in ER retention.
Luminal breast tumors typically have a lower risk of metastasis due to the epithelial nature of the cells. Strong adhesion between epithelial cancer cells lowers their motility, migration rate, and invasive potential. Despite the nature of epithelial breast tumors, they may still undergo metastasis, which is thought to be initiated by epithelial-mesenchymal transition (EMT). EMT is a process through which epithelial cells acquire the phenotype of mesenchymal cells, which have enhanced invasive potential in cancer. MicroRNAs, small regulatory RNAs that inhibit gene expression, play a role in the regulation of EMT. This study demonstrates that microRNA-100 (miR-100) is upregulated in mesenchymal breast cancer cells (MCF-7M) versus epithelial breast cancer cells (MCF-7) via a mammosphere-induced EMT. MiR-100 may play a role in EMT by targeting the insulin like growth factor 1 receptor (IGF1R). Inhibition of miR-100 in MCF-7M cells significantly increased endogenous IGF1R expression. IGF1R has been implemented in the initiation of tumorigenesis; however expression of this receptor also strengthens E-cadherin mediated adhesion in epithelial cells. It is hypothesized that upregulation of miR-100 in mesenchymal breast cancer cells decreases IGF1R expression to facilitate increased motility and invasive potential, and inhibition of miR-100 in mesenchymal breast cancer cells (MCF-7M) resulted in decreased cell migration. This study enhances the understanding of the role of microRNAs in breast cancer metastasis, and may provide novel targets or biomarkers of cancer progression.
Clostridium difficile is a gram positive spore forming bacteria that is the primary cause of antibiotic associated diarrheas in the United States and Europe. The prevalence of C. difficile infections (CDI) in hospitals and long term care facilities has increased over the past decade and now represents a serious threat to patient health. Because C. difficile infections are caused by antibiotic therapy, alternative means of treatment are of interest. This study investigates the prevalence of C. difficile infection in three community hospitals and one research hospital and compares hospital prevalence data to state averages for Alabama and Mississippi and the national average. It was found that one community hospital exceeded the national average while two community hospitals and the research hospital were less than the national average of CDI. Both the standard infection ratio for C. difficile for Alabama and Mississippi were less than the national average. Data for January 1, 2013 – June 3, 2013 are included. To better control CDI, the Centers for Disease Control and Prevention (CDC) recommends better antibiotic stewardship, training for clinical pharmacists, and limited prescription of antibiotics for hospital and long term care facility patients. Alternative treatments for recurrent or non-responsive C. difficile infections include transplantation of fecal microbiota and probiotics. Several vaccines for C. difficile are currently under development or in clinical trials.