http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Structural evidence of <b>α</b>‐aminoacylated lipoproteins of <i>Staphylococcus aureus</i>
Asanuma, Miwako,Kurokawa, Kenji,Ichikawa, Rie,Ryu, Kyoung‐,Hwa,Chae, Jun‐,Ho,Dohmae, Naoshi,Lee, Bok Luel,Nakayama, Hiroshi Blackwell Publishing Ltd 2011 FEBS JOURNAL Vol.278 No.5
<P>Bacterial lipoproteins are known to be diacylated or triacylated and activate mammalian immune cells via Toll‐like receptor 2/6 or 2/1 heterodimer. Because the genomes of low G+C content Gram‐positive bacteria, such as <I>Staphylococcus aureus</I>, do not contain <I>Escherichia coli</I>‐type apolipoprotein <I>N</I>‐acyltransferase, an enzyme converting diacylated lipoproteins into triacylated forms, it has been widely believed that native lipoproteins of <I>S. aureus</I> are diacylated. However, we recently demonstrated that one lipoprotein SitC purified from <I>S. aureus</I> RN4220 strain was triacylated. Almost simultaneously, another group reported that another lipoprotein SA2202 purified from <I>S. aureus</I> SA113 strain was diacylated. The determination of exact lipidated structures of <I>S. aureus</I> lipoproteins is thus crucial for elucidating the molecular basis of host–microorganism interactions. Toward this purpose, we intensively used MS‐based analyses. Here, we demonstrate that SitC lipoprotein of <I>S. aureus</I> RN4220 strain has two lipoprotein lipase‐labile <I>O</I>‐esterified fatty acids and one lipoprotein lipase‐resistant fatty acid. Further MS/MS analysis of the lipoprotein lipase digest revealed that the lipoprotein lipase‐resistant fatty acid was acylated to α‐amino group of the N‐terminal cysteine residue of SitC. Triacylated forms of SitC with various length fatty acids were also confirmed in cell lysate of the RN4220 and Triton X‐114 phase in three other <I>S. aureus</I> strains, including SA113 strain and one <I>Staphylococcus epidermidis</I> strain. Moreover, four other major lipoproteins including SA2202 in <I>S. aureus</I> strains were identified as <I>N</I>‐acylated. These results strongly suggest that lipoproteins of <I>S. aureus</I> are mainly in the <I>N</I>‐acylated triacyl form.</P>
Kurokawa, Kenji,Ryu, Kyoung-Hwa,Ichikawa, Rie,Masuda, Akiko,Kim, Min-Su,Lee, Hanna,Chae, Jun-Ho,Shimizu, Takashi,Saitoh, Tatsuya,Kuwano, Koichi,Akira, Shizuo,Dohmae, Naoshi,Nakayama, Hiroshi,Lee, Bok American Society for Biochemistry and Molecular Bi 2012 The Journal of biological chemistry Vol.287 No.16
Kurokawa, Kenji,Lee, Hanna,Roh, Kyung-Baeg,Asanuma, Miwako,Kim, Young Sook,Nakayama, Hiroshi,Shiratsuchi, Akiko,Choi, Youngnim,Takeuchi, Osamu,Kang, Hee Jung,Dohmae, Naoshi,Nakanishi, Yoshinobu,Akira, American Society for Biochemistry and Molecular Bi 2009 The Journal of biological chemistry Vol.284 No.13
<P>Some synthetic lipopeptides, in addition to native lipoproteins derived from both Gram-negative bacteria and mycoplasmas, are known to activate TLR2 (Toll-like receptor 2). However, the native lipoproteins inherent to Gram-positive bacteria, which function as TLR2 ligands, have not been characterized. Here, we have purified a native lipoprotein to homogeneity from Staphylococcus aureus to study as a native TLR2 ligand. The purified 33-kDa lipoprotein was capable of stimulating TLR2 and was identified as a triacylated SitC lipoprotein, which belongs to a family of ATP binding cluster (ABC) transporter substrate-binding proteins. Analyses of the SitC-mediated production of cytokine using mouse peritoneal macrophages revealed that the SitC protein (3 nm) induced the production of tumor necrosis factor-alpha and interleukin-6. Moreover, analysis of knock-out mice showed that SitC required TLR2 and MyD88, but not TLR1 or TLR6, for the induction of cytokines. In addition to the S. aureus SitC lipoprotein, we purified two other native ABC transporter substrate-binding lipoproteins from Bacillus subtilis and Micrococcus luteus, which were both shown to stimulate TLR2. These results demonstrate that S. aureus SitC lipoprotein is triacylated and that the ABC transporter substrate-binding lipoproteins of Gram-positive bacteria function as native ligands for TLR2.</P>
Kim, Jiyeun Kate,Won, Yeo Jin,Nikoh, Naruo,Nakayama, Hiroshi,Han, Sang Heum,Kikuchi, Yoshitomo,Rhee, Young Ha,Park, Ha Young,Kwon, Jeong Yun,Kurokawa, Kenji,Dohmae, Naoshi,Fukatsu, Takema,Lee, Bok Lue National Academy of Sciences 2013 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.110 No.26
<P>Many bacteria accumulate granules of polyhydroxyalkanoate (PHA) within their cells, which confer resistance to nutritional depletion and other environmental stresses. Here, we report an unexpected involvement of the bacterial endocellular storage polymer, PHA, in an insect–bacterium symbiotic association. The bean bug <I>Riptortus pedestris</I> harbors a beneficial and specific gut symbiont of the β-proteobacterial genus <I>Burkholderia</I>, which is orally acquired by host nymphs from the environment every generation and easily cultivable and genetically manipulatable. Biochemical and cytological comparisons between symbiotic and cultured <I>Burkholderia</I> detected more PHA granules consisting of poly-3-hydroxybutyrate and associated phasin (PhaP) protein in the symbiotic <I>Burkholderia</I>. Among major PHA synthesis genes, <I>phaB</I> and <I>phaC</I> were disrupted by homologous recombination together with the <I>phaP</I> gene, whereby <I>ΔphaB</I>, <I>ΔphaC</I>, and <I>ΔphaP</I> mutants were generated. Both in culture and in symbiosis, accumulation of PHA granules was strongly suppressed in <I>ΔphaB</I> and <I>ΔphaC</I>, but only moderately in <I>ΔphaP.</I> In symbiosis, the host insects infected with <I>ΔphaB</I> and <I>ΔphaC</I> exhibited significantly lower symbiont densities and smaller body sizes. These deficient phenotypes associated with <I>ΔphaB</I> and <I>ΔphaC</I> were restored by complementation of the mutants with plasmids encoding a functional <I>phaB</I>/<I>phaC</I> gene. Retention analysis of the plasmids revealed positive selection acting on the functional <I>phaB</I>/<I>phaC</I> in symbiosis. These results indicate that the PHA synthesis genes of the <I>Burkholderia</I> symbiont are required for normal symbiotic association with the <I>Riptortus</I> host. In vitro culturing analyses confirmed vulnerability of the PHA gene mutants to environmental stresses, suggesting that PHA may play a role in resisting stress under symbiotic conditions.</P>