Characterisation of the enzyme transport path between shipworms and their bacterial symbionts.
Characterisation of the enzyme transport path between shipworms and their bacterial symbionts.
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DOI：
10.1186/s12915-021-01162-6
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发表时间：
2021-11-01
期刊：
影响因子：
5.4
通讯作者：
McQueen-Mason SJ
中科院分区：
文献类型：
--
作者：
Pesante G;Sabbadin F;Elias L;Steele-King C;Shipway JR;Dowle AA;Li Y;Busse-Wicher M;Dupree P;Besser K;Cragg SM;Bruce NC;McQueen-Mason SJ
船蛆是海洋食木双壳类软体动物，由于它们能够产生植物细胞壁降解酶，因此可以仅以木材为食。细菌碳水化合物活性酶（CAZymes），由生活在称为细菌细胞的专门的船蛆细胞中的内共生体合成，位于动物的鳃中，在船蛆的木材消化中发挥重要作用。然而，木质纤维素消化的主要网站在这些木材钻孔软体动物，其中包含内源性木质纤维素分解酶和原核酶，是盲肠，和细菌酶到达遥远的盲肠腔的机制至今仍然是神秘的。在这里，我们提供了一个表征的路径，通过该路径产生的细菌CAZymes在鳃的石首虫到达遥远的盲肠，有助于木材的消化。通过转录组学，蛋白质组学，X射线显微断层扫描，电子显微镜研究和体外生物化学表征相结合，我们表明，木材消化酶产生的共生细菌不仅局限于鳃，但也在管腔的食物槽，流的粘液分泌的鳃细胞携带食物颗粒过滤器喂养到嘴。细菌的CAZyme也存在于水晶风格和盲肠中的船蛆宿主，这表明了一个独特的途径，参与共生相互作用的酶被运送到它们的作用部位。最后，我们在体外鉴定了四种新的细菌糖基水解酶和一种溶解性多糖单加氧酶，这些酶在我们的转录组学和蛋白质组学分析中被鉴定为参与这种不寻常的生物系统的一些主要细菌酶。根据我们的数据，我们提出，细菌和它们的酶从鳃沿着食物槽运输到船蛆的嘴和消化道，在那里它们帮助木材消化。在线版本包含补充材料，可通过10.1186/s12915-021-01162-6获得。
Shipworms are marine xylophagus bivalve molluscs, which can live on a diet solely of wood due to their ability to produce plant cell wall-degrading enzymes. Bacterial carbohydrate-active enzymes (CAZymes), synthesised by endosymbionts living in specialised shipworm cells called bacteriocytes and located in the animal’s gills, play an important role in wood digestion in shipworms. However, the main site of lignocellulose digestion within these wood-boring molluscs, which contains both endogenous lignocellulolytic enzymes and prokaryotic enzymes, is the caecum, and the mechanism by which bacterial enzymes reach the distant caecum lumen has remained so far mysterious. Here, we provide a characterisation of the path through which bacterial CAZymes produced in the gills of the shipworm Lyrodus pedicellatus reach the distant caecum to contribute to the digestion of wood. Through a combination of transcriptomics, proteomics, X-ray microtomography, electron microscopy studies and in vitro biochemical characterisation, we show that wood-digesting enzymes produced by symbiotic bacteria are localised not only in the gills, but also in the lumen of the food groove, a stream of mucus secreted by gill cells that carries food particles trapped by filter feeding to the mouth. Bacterial CAZymes are also present in the crystalline style and in the caecum of their shipworm host, suggesting a unique pathway by which enzymes involved in a symbiotic interaction are transported to their site of action. Finally, we characterise in vitro four new bacterial glycosyl hydrolases and a lytic polysaccharide monooxygenase identified in our transcriptomic and proteomic analyses as some of the major bacterial enzymes involved in this unusual biological system. Based on our data, we propose that bacteria and their enzymes are transported from the gills along the food groove to the shipworm’s mouth and digestive tract, where they aid in wood digestion. The online version contains supplementary material available at 10.1186/s12915-021-01162-6.
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影响因子：
3.7
作者：
Brito TL;Campos AB;Bastiaan von Meijenfeldt FA;Daniel JP;Ribeiro GB;Silva GGZ;Wilke DV;de Moraes DT;Dutilh BE;Meirelles PM;Trindade-Silva AE
通讯作者：
Trindade-Silva AE
影响因子：
7.8
作者：
Cragg SM;Beckham GT;Bruce NC;Bugg TD;Distel DL;Dupree P;Etxabe AG;Goodell BS;Jellison J;McGeehan JE;McQueen-Mason SJ;Schnorr K;Walton PH;Watts JE;Zimmer M
通讯作者：
Zimmer M
影响因子：
4.4
作者：
Distel, DL;Beaudoin, DJ;Morrill, W
通讯作者：
Morrill, W
影响因子：
7.2
作者：
Bromley, Jennifer R.;Busse-Wicher, Marta;Dupree, Paul
通讯作者：
Dupree, Paul
影响因子：
0.5
作者：
Alyakrinskaya, IO
通讯作者：
Alyakrinskaya, IO