Vibrio splendidus is an important opportunistic pathogen ubiquitously present in the marine environment,exhibiting virulence to a variety of cultured animals.The extracellular products secreted by V.splendidus are cru...Vibrio splendidus is an important opportunistic pathogen ubiquitously present in the marine environment,exhibiting virulence to a variety of cultured animals.The extracellular products secreted by V.splendidus are crucial to bacterial survival and virulence.In this study,the secretion of outer membrane vesicles(OMVs)by V.splendidus was determined,purified,and morphologically characterized.The protein composition of OMVs was analyzed by proteomic analysis.The results showed that approximately 120 proteins were contained in these OMVs,including outer membrane proteins,flagellins,ABC transporters,protease,and iron regulation proteins,etc.,which were involved in bacterial motility,formation of biofilms and the cell membrane components,and cellular localization based on their structural molecule activity,passive transmembrane transporter activity,channel activity,neurotransmitter receptor activity,extracellular ligand-gated ion channel activity,glutamate receptor activity,ligand-gated ion channel activity,and transmembrane signaling receptor activity.To explore the biological functions of OMVs in V.splendidus,the effects of OMVs on the bacterial adaption to iron limitation,antibiotic,and the coelomic fluid of the Apostichopus japonicus were confirmed.This study is the first time to show that V.splendidus secretes OMVs,and OMVs carry functional proteins that enhance bacterial survival under various stresses.展开更多
The p21-activated kinase 1(PAK1)is a downstream serine/threonine kinase effector of Rac1/Cdc42 that regulates various biological processes including those associating with pathological inflammation.To investigate the ...The p21-activated kinase 1(PAK1)is a downstream serine/threonine kinase effector of Rac1/Cdc42 that regulates various biological processes including those associating with pathological inflammation.To investigate the function of PAK1 in echinoderms,we isolated a new PAK1 from sea cucumber Apostichopus japonicus(AjPAK1)by transcriptome database mining and with rapid amplification of cDNA ends(RACE).The full-length cDNA AjPAK1 was 2303 bp in length,containing a 1587 bp ORF encoding 528 amino acid residues.The deduced AjPAK1 contained a p21-Rho-binding domain(PBD)and a serine/threonine protein kinase catalytic domain(S_TKc),which was similar to the PAK1 of crown-of-thorns starfish Acanthaster planci and other eukaryotes.AjPAK1 expressed in all tissues of adult A.japonicus analyzed with the highest transcript anumdance detected in coelomocytes.Significant change in AjPAK1 abundance was observed at 4,24,48 and 72 h after Vibrio splendidus infection.Silencing AjPAK1 induced a significant reduction of lysozyme content in coelomic fluid and relative transcript abundances of AjRac1 and AjMKK3/6 in A.japonicus coelomocytes.These results should aid to characterize PAK1 of sea cucumber and decipher its immune function.展开更多
基金the Zhejiang Provincial Natural Science Foundation for Distinguished Young Scholars(No.LR20C190001)the National Natural Science Foundation of China(No.31972833)+1 种基金the Fundamental Research Funds for the Provincial Universities of Zhejiang(No.SJ LZ2020001)the K.C.Wong Magna Fund at Ningbo University。
文摘Vibrio splendidus is an important opportunistic pathogen ubiquitously present in the marine environment,exhibiting virulence to a variety of cultured animals.The extracellular products secreted by V.splendidus are crucial to bacterial survival and virulence.In this study,the secretion of outer membrane vesicles(OMVs)by V.splendidus was determined,purified,and morphologically characterized.The protein composition of OMVs was analyzed by proteomic analysis.The results showed that approximately 120 proteins were contained in these OMVs,including outer membrane proteins,flagellins,ABC transporters,protease,and iron regulation proteins,etc.,which were involved in bacterial motility,formation of biofilms and the cell membrane components,and cellular localization based on their structural molecule activity,passive transmembrane transporter activity,channel activity,neurotransmitter receptor activity,extracellular ligand-gated ion channel activity,glutamate receptor activity,ligand-gated ion channel activity,and transmembrane signaling receptor activity.To explore the biological functions of OMVs in V.splendidus,the effects of OMVs on the bacterial adaption to iron limitation,antibiotic,and the coelomic fluid of the Apostichopus japonicus were confirmed.This study is the first time to show that V.splendidus secretes OMVs,and OMVs carry functional proteins that enhance bacterial survival under various stresses.
基金supported by the National Key R&D Program of China (No. 2018YFD0900105)
文摘The p21-activated kinase 1(PAK1)is a downstream serine/threonine kinase effector of Rac1/Cdc42 that regulates various biological processes including those associating with pathological inflammation.To investigate the function of PAK1 in echinoderms,we isolated a new PAK1 from sea cucumber Apostichopus japonicus(AjPAK1)by transcriptome database mining and with rapid amplification of cDNA ends(RACE).The full-length cDNA AjPAK1 was 2303 bp in length,containing a 1587 bp ORF encoding 528 amino acid residues.The deduced AjPAK1 contained a p21-Rho-binding domain(PBD)and a serine/threonine protein kinase catalytic domain(S_TKc),which was similar to the PAK1 of crown-of-thorns starfish Acanthaster planci and other eukaryotes.AjPAK1 expressed in all tissues of adult A.japonicus analyzed with the highest transcript anumdance detected in coelomocytes.Significant change in AjPAK1 abundance was observed at 4,24,48 and 72 h after Vibrio splendidus infection.Silencing AjPAK1 induced a significant reduction of lysozyme content in coelomic fluid and relative transcript abundances of AjRac1 and AjMKK3/6 in A.japonicus coelomocytes.These results should aid to characterize PAK1 of sea cucumber and decipher its immune function.
