No abstract

Bacillus thuringiensis Sip proteins are secreted insecticidal toxins that are toxic to coleopteran pests. In this study, we investigated the transcriptional mechanism of the sip gene and showed strong evidence that Sip1Ab1 is secreted in the transition phase and that AbrB, a transition phase regulator that is usually a repressor, positively and directly regulates sip1Ab1 .

The expression of anillin mRNA and protein is regulated in a cell cycle-dependent manner. However, the mechanism underlying this process is unclear. Previous studies analyzing the sequence of the 5'-untranslated region of anillin have unveiled several putative p53 binding sites. Therefore, the present study hypothesized that the anillin gene may be repressed by p53 and that the commonly observed mutation (or loss of function) of p53 may serve a role in this phenotype. Bioinformatic analysis of the anillin promoter region revealed potential p53 responsive elements. Of those identified, 2 were able to bind p53 protein, as determined via a chromatin immunoprecipitation assay. Although it was hypothesized that dNA damage and resultant p53 expression would repress anillin expression, the results revealed that anillin mRNA and protein expression levels were negatively regulated by dNA damage in the wild-type p53 cells, but not in the isogenic p53 null cells. Furthermore, dNA sequences encompassing the p53 binding site downregulated luciferase transgenes in a p53 dependent manner. Taken together, these data indicated that anillin was negatively regulated by p53 and that anillin overexpression observed in cancer may be a p53-mediated phenomenon. The data from the present study provided further evidence for the role of p53 in the biologically crucial process of cytokinesis.