title: A specific cathepsin-L-like protease purified from an insect midgut shows antibacterial activity against gut symbiotic bacteria.
abstract: Because gut symbiotic bacteria affect host biology, host insects are expected to evolve some mechanisms for regulating symbiont population. The bean bug, Riptortus pedestris, harbors the Burkholderia genus as a gut symbiont in the midgut organ, designated as the M4 region. Recently, we demonstrated that the lysate of M4B, the region adjacent to M4, harbors potent antibacterial activity against symbiotic Burkholderia but not to cultured Burkholderia. However, the bona fide substance responsible for observed antibacterial activity was not identified in the previous study. Here, we report that cathepsin-L-like protease purified from the lysate of M4B showed strong antibacterial activity against symbiotic Burkholderia but not the cultured Burkholderia. To further confirm this activity, recombinant cathepsin-L-like protease expressed in Escherichia coli also showed antibacterial activity against symbiotic Burkholderia. These results suggest that cathepsin-L-like protease purified from the M4B region plays a critical role in controlling the population of the Burkholderia gut symbiont.
authors.affiliation: Global Research Laboratory of Insect Symbiosis, College of Pharmacy, Pusan National University, Busan 609-735, Republic of Korea.
authors.forename: Jin Hee
authors.initials: JH
authors.lastname: Byeon
authors.affiliation: Global Research Laboratory of Insect Symbiosis, College of Pharmacy, Pusan National University, Busan 609-735, Republic of Korea.
authors.forename: Eun Sil
authors.initials: ES
authors.lastname: Seo
authors.affiliation: Global Research Laboratory of Insect Symbiosis, College of Pharmacy, Pusan National University, Busan 609-735, Republic of Korea.
authors.forename: Jun Beom
authors.initials: JB
authors.lastname: Lee
authors.affiliation: Global Research Laboratory of Insect Symbiosis, College of Pharmacy, Pusan National University, Busan 609-735, Republic of Korea.
authors.forename: Min Ja
authors.initials: MJ
authors.lastname: Lee
authors.affiliation: Department of Microbiology, Kosin University College of Medicine, Busan 602-703, Republic of Korea.
authors.forename: Jiyeun Kate
authors.initials: JK
authors.lastname: Kim
authors.affiliation: Global Research Laboratory of Insect Symbiosis, College of Pharmacy, Pusan National University, Busan 609-735, Republic of Korea.
authors.forename: Jin Wook
authors.initials: JW
authors.lastname: Yoo
authors.affiliation: Global Research Laboratory of Insect Symbiosis, College of Pharmacy, Pusan National University, Busan 609-735, Republic of Korea.
authors.forename: Yunjin
authors.initials: Y
authors.lastname: Jung
authors.affiliation: Global Research Laboratory of Insect Symbiosis, College of Pharmacy, Pusan National University, Busan 609-735, Republic of Korea. Electronic address: brlee@pusan.ac.kr.
authors.forename: Bok Luel
authors.initials: BL
authors.lastname: Lee
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D019117:Burkholderia / Q000187:drug effects* / Q000254:growth & development; D056668:Cathepsin L / Q000378:metabolism / Q000494:pharmacology*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D000069196:Gastrointestinal Microbiome / Q000187:drug effects* / Q000276:immunology; D041981:Gastrointestinal Tract / Q000382:microbiology; D020062:Heteroptera / Q000276:immunology / Q000382:microbiology*; D008969:Molecular Sequence Data; D013559:Symbiosis
chemical_list: D000900:Anti-Bacterial Agents; D056668:Cathepsin L
keywords: Burkholderia; Cathepsin L; Gut symbiosis; Riptortus pedestris; Symbiont population