• Journal of Life Science
• /
• v.26 no.2
• /
• pp.265-274
• /
• 2016

Toxin-antitoxin (TA) systems are ubiquitous genetic modules that are evolutionally conserved in bacteria and archaea. TA systems composed of an intracellular toxin and its antidote (antitoxin) are currently classified into five types. Commonly, activation of toxins under stress conditions inhibits diverse cellular processes and consequently induces cell death or reversible growth inhibition. These effects of toxins play various physiological roles in such as regulation of gene expression, growth control (stress response), programmed cell arrest, persister cells, programmed cell death, phage protection, stabilization of mobile genetic elements or postsegregational killing of plasmid-free cells. Accordingly, bacterial TA systems are commonly considered as stress-responsive genetic modules. However, molecule screening for activation of toxin in TA system is available as development of antimicrobial agents. In addition, cytotoxic effect induced by toxin is used as effective cloning method with antitoxic effect of antitoxin; consequently cells containing cloning vector inserted a target gene can survive and false-positive transformants are removed. Also, TA system is applicable to efficient single protein production in biotechnology industry because toxins that are site-specific ribonuclease inhibit protein synthesis except for target protein. Furthermore, some TA systems that induce apoptosis in eukaryotic cells such as cancer cells or virus-infected cells would have a wide range of applications in eukaryotes, and it will lead to new ways of treating human disease. In this review, we summarize the current knowledge on bacterial TA systems and their applications.

• Journal of Society of Preventive Korean Medicine
• /
• v.7 no.1
• /
• pp.79-86
• /
• 2003

This study was carried out to evaluate cytotoxic effects of Houttuynia cordata $T_{HUNB}$ extracts on A549(lung cancer), B16(mouse melanoma), MDA-MB231(breast cancer) and SNU-C4(colon cancer) cell lines. We have determined by 3-(4, 5-dimethylthiazol-2-Yl)-2, 5-diphenyl-2H-tetrazoliumbromide(MTT) assay. The $150{\mu}g/ml$ concentration of chloroform extract of Houttuynia cordata $T_{HUNB}$ was shown significantly antitoxic activity on MDA-MB231$(65.96{\pm}5.68%)$ and SNU-C4$(55.94{\pm}7.39%)$ cell lines.