XaxAB‐like binary toxin from Photorhabdus luminescens exhibits both insecticidal activity and cytotoxicity. Issue 1 (22nd November 2013)

• Record Type: Journal Article
• Authors: Zhang, Xu; Hu, Xiaofeng; Li, Yusheng; Ding, Xuezhi; Yang, Qi; Sun, Yunjun; Yu, Ziquan; Xia, Liqiu; Hu, Shengbiao
• Is Part Of: FEMS microbiology letters. Volume 350:Issue 1(2014:Jan.)
• Page Start: 48
• Page End: 56
• Publication Date: 2013-11-22
• Subjects: Microbiology -- Periodicals; 579
• DOI: 10.1111/1574-6968.12321
• Languages: English
• ISSNs: 0378-1097

Abstract

<abstract abstract-type="main" id="fml12321-abs-0001"> <title>Abstract</title> <p>The enterobacterium <italic>Photorhabdus luminescens</italic> produces a number of toxins to kill its insect host. By analyzing the genomic sequence of <italic>P. luminescens </italic>TT01, we found that amino acid sequences encoded by <italic>plu1961</italic> and <italic>plu1962</italic> showed high similarity to XaxAB binary toxin of <italic>Xenorhabuds nematophila</italic>, which has both necrotic and apoptotic activities in both insect and mammalian cells <italic>in vitro</italic>. To evaluate the biological activity of Plu1961/Plu1962, their coding genes were cloned and expressed in <italic>Escherichia coli</italic>. Both Plu1961 and Plu1962 were expressed as soluble protein in BL21 (DE3) and their mixture caused insect midgut CF‐203 cells death via necrosis. Confocal fluorescence microscopy showed that Plu1961/Plu1962 mixture was able to depolymerize microtubule and induce the increase in plasma membrane permeabilization in CF‐203 cells. Moreover, co‐expression of Plu1961/Plu1962 in the same cytoplasm exhibited cytotoxic effect against mammalian cells (B16, 4T1, and HeLa cells) and injectable activity against <italic>Spodoptera exigua</italic> larvae. Until now, two types of binary toxins have been identified in <italic>P. luminescens</italic>, the first type is PirAB and Plu1961/Plu1962 is the second one. The biological role of Plu1961/Plu1962 binary toxin played in the infection process should attract more attention in future.</p> </abstract>