Photorhabdus luminescens PirAB-fusion protein exhibits both cytotoxicity and insecticidal activity.
The binary toxin 'Photorhabdus insect-related' proteins (PirAB) produced by Photorhabdus luminescens have been reported to possess both injectable and oral activities against a range of insects. Here, PirAB-fusion protein was constructed by linking pirA and pirB genes with the flexible linker (Gly4 Ser)3 DNA encoding sequence and then efficiently expressed in Escherichia coli. To better understand the role of PirAB toxin played in the process of invasion, its cytotoxicity against insect midgut CF-203 cells was investigated. Application of purified PirAB-fusion protein as well as PirA/PirB mixture caused loss of viability of CF-203 cells after 24 h incubation. CF-203 cells treated by PirAB-fusion protein displayed morphological changes typical of apoptosis, such as cell shrinkage, cell membrane blebbing, nuclear condensation and DNA fragmentation. Moreover, PirAB-fusion protein also exhibited injectable insecticidal activity against Spodoptera exigua larvae. The bodies of S. exigua fourth-instar larvae injected with PirAB-fusion protein turned completely black. Thus, we concluded that PirAB-fusion protein possessed similar biological activity (cytotoxicity and insecticidal activity) to PirA/PirB mixture, which would enable it to be used as an efficient agent for pest control.
College of Life Sciences, Hunan Provincial Key Laboratory of Microbial Molecular Biology - State Key Laboratory Breeding Base of Microbial Molecular Biology, Hunan Normal University, Changsha, China.
Yusheng
Y
Li
Xiaofeng
X
Hu
Xu
X
Zhang
Zhengqiang
Z
Liu
Xuezhi
X
Ding
Liqiu
L
Xia
Shengbiao
S
Hu
D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology*; D001427:Bacterial Toxins / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology*; D001483:Base Sequence; D002460:Cell Line; D048430:Cell Shape / Q000187:drug effects; D002470:Cell Survival; D004926:Escherichia coli; D007306:Insecticides / Q000378:metabolism / Q000494:pharmacology*; D007814:Larva / Q000187:drug effects; D008969:Molecular Sequence Data; D020637:Photorhabdus / Q000737:chemistry*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology*; D018411:Spodoptera / Q000187:drug effects
D001426:Bacterial Proteins; D001427:Bacterial Toxins; D007306:Insecticides; D011993:Recombinant Fusion Proteins
Photorhabdus luminescens; PirAB; apoptosis; cytotoxicity; fusion protein; injectable activity