Lethality of sortase depletion in Actinomyces oris caused by excessive membrane accumulation of a surface glycoprotein.
Lethality of sortase depletion in Actinomyces oris caused by excessive membrane accumulation of a surface glycoprotein.
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表面糖蛋白的过度膜积聚引起的放线菌分子酶耗竭的致死性。
DOI：
10.1111/mmi.12780
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发表时间：
2014-12
影响因子：
3.6
通讯作者：
Ton-That H
中科院分区：
文献类型：
--
作者：
Wu C;Huang IH;Chang C;Reardon-Robinson ME;Das A;Ton-That H
分选酶是革兰氏阳性细菌中保守的一种半胱氨酸转肽酶，将许多促进细菌发病机制和适应度的表面蛋白锚定在细胞壁上。迄今为止报道的几种革兰氏阳性病原体的管家分选酶的基因破坏会减弱毒力，但不会减弱细菌的生长。矛盾的是，我们发现管家分选酶 SrtA 的消耗对于放线菌来说是致命的。然而，其所有预测的细胞壁锚定蛋白底物（AcaA-N）对于细胞活力来说都是单独可有可无的。利用 Tn5 转座子诱变来鉴定影响 srtA 缺失致死率的因素，我们发现了一组基因抑制子，这些基因抑制子在编码 AcaC 和 LytR-CpsA-Psr (LCP) 样蛋白的基因座内含有转座子插入。 AcaC 被证明是高度糖基化的并且依赖于 LCP 的糖基化。 SrtA 耗尽后，AcaC 的糖基化形式（特此更名为 GspA）在膜中积累。在缺乏 gspA 和 srtA 的突变体中，GspA 的过度表达是致命的；相反，过度表达缺失膜定位域的 GspA 突变体的细胞是可行的。结果揭示了 A. oris 中独特的糖基化途径，该途径与分选酶 SrtA 催化的细胞壁锚定偶联。值得注意的是，这种新的糖应激现象为开发一类针对革兰氏阳性病原体的新型抑制剂提供了方便的基于细胞的测定。
Sortase, a cysteine-transpeptidase conserved in Gram-positive bacteria, anchors on the cell wall many surface proteins that facilitate bacterial pathogenesis and fitness. Genetic disruption of the housekeeping sortase in several Gram-positive pathogens reported thus far attenuates virulence, but not bacterial growth. Paradoxically, we discovered that depletion of the housekeeping sortase SrtA was lethal for Actinomyces oris; yet, all of its predicted cell wall-anchored protein substrates (AcaA-N) were individually dispensable for cell viability. Using Tn5-transposon mutagenesis to identify factors that upend lethality of srtA deletion, we uncovered a set of genetic suppressors harboring transposon insertions within genes of a locus encoding AcaC and a LytR-CpsA-Psr (LCP)-like protein. AcaC was shown to be highly glycosylated and dependent on LCP for its glycosylation. Upon SrtA depletion, the glycosylated form of AcaC, hereby renamed GspA, was accumulated in the membrane. Overexpression of GspA in a mutant lacking gspA and srtA was lethal; conversely, cells overexpressing a GspA mutant missing a membrane-localization domain were viable. The results reveal a unique glycosylation pathway in A. oris that is coupled to cell wall anchoring catalyzed by sortase SrtA. Significantly, this novel phenomenon of glyco-stress provides convenient cell-based assays for developing a new class of inhibitors against Gram-positive pathogens.
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影响因子：
3.2
作者：
Nielsen, Hailyn V.;Flores-Mireles, Ana L.;Hultgren, Scott J.
通讯作者：
Hultgren, Scott J.
DOI：
10.1073/pnas.1321417111
发表时间：
2014-03-11
影响因子：
11.1
作者：
Reardon-Robinson, Melissa E.;Wu, Chenggang;Hung Ton-That
通讯作者：
Hung Ton-That
影响因子：
2.6
作者：
Corrigan, Rebecca M.;Foster, Timothy J.
通讯作者：
Foster, Timothy J.
DOI：
10.1073/pnas.080520697
发表时间：
2000-05-09
影响因子：
11.1
作者：
Mazmanian, SK;Liu, G;Schneewind, O
通讯作者：
Schneewind, O
影响因子：
9.4
作者：
JOYCE, LF;DOWNES, J;ANDREW, JH
通讯作者：
ANDREW, JH