Fasciclin family proteins have been identified as cell adhesion molecules in various organisms. In this study, a novel Magnaporthe oryzae fasciclin-like protein encoding gene, named MoFLP1, was isolated from a subtrac...Fasciclin family proteins have been identified as cell adhesion molecules in various organisms. In this study, a novel Magnaporthe oryzae fasciclin-like protein encoding gene, named MoFLP1, was isolated from a subtractive suppressive cDNA library and functionally analyzed. Sequence analysis showed that the MoFLP1 gene contains an open reading frame (ORF) of 1050 nucleotides encoding 349 amino acids with a calculated molecular weight of 35.85 kDa and a pI of 7.76. The deduced MoFLP1 protein contains a 17-amino acid secretion signal sequence and an 18-amino acid sequence with the characteristics of a glycosylphosphotidylinositol (GPI) anchor additional signal at its N- and C-terminuses, respectively. Potential N-glycosylation sites and domains involving cell adhesion were also identified in MoFLP1. Sequence analysis and subcellular localization by the expression of MoFLP1-GFP fusion construct in M. oryzae indicated that the MoFLP1 protein is probably localized on the vacuole membrane. Two MoFLP1 null mutants generated by targeted gene disruption exhibited marked reduction of conidiation, conidial adhesion, appressorium turgor, and pathogenicity. Our results indicate that fasciclin proteins play important roles in fungal de-velopment and pathogenicity in M. oryzae.展开更多
During infections,bacteria stimulate host cells to produce and release histamine,which is a key mediator of vital cellular processes in animals.However,the mechanisms underlying the bacterial cell’s ability to sense ...During infections,bacteria stimulate host cells to produce and release histamine,which is a key mediator of vital cellular processes in animals.However,the mechanisms underlying the bacterial cell’s ability to sense and respond to histamine are poorly understood.Herein,we show that HinK,a Lys R-type transcriptional regulator,is required to evoke responses to histamine in Pseudomonas aeruginosa,an important human pathogen.HinK directly binds to and activates the promoter of genes involved in histamine uptake and metabolism,iron acquisition,and Pseudomonas quinolone signal(PQS)biosynthesis.The transcriptional regulatory activity of HinK is induced when histamine is present,and it occurs when HinK binds with imidazole-4-acetic acid(Im AA),a histamine metabolite whose production in P.aeruginosa depends on the HinK-activated histamine uptake and utilization operon hin DAC-pa0222.Importantly,the inactivation of HinK inhibits diverse pathogenic phenotypes of P.aeruginosa.These results suggest that histamine acts as an interkingdom signal and provide insights into the mechanism used by pathogenic bacteria to exploit host regulatory signals to promote virulence.展开更多
基金Project supported by the National Natural Science Foundation of China (No. 30870101)the Public Welfare Profession (Agricul-ture) Research Project (No. 200803008), China
文摘Fasciclin family proteins have been identified as cell adhesion molecules in various organisms. In this study, a novel Magnaporthe oryzae fasciclin-like protein encoding gene, named MoFLP1, was isolated from a subtractive suppressive cDNA library and functionally analyzed. Sequence analysis showed that the MoFLP1 gene contains an open reading frame (ORF) of 1050 nucleotides encoding 349 amino acids with a calculated molecular weight of 35.85 kDa and a pI of 7.76. The deduced MoFLP1 protein contains a 17-amino acid secretion signal sequence and an 18-amino acid sequence with the characteristics of a glycosylphosphotidylinositol (GPI) anchor additional signal at its N- and C-terminuses, respectively. Potential N-glycosylation sites and domains involving cell adhesion were also identified in MoFLP1. Sequence analysis and subcellular localization by the expression of MoFLP1-GFP fusion construct in M. oryzae indicated that the MoFLP1 protein is probably localized on the vacuole membrane. Two MoFLP1 null mutants generated by targeted gene disruption exhibited marked reduction of conidiation, conidial adhesion, appressorium turgor, and pathogenicity. Our results indicate that fasciclin proteins play important roles in fungal de-velopment and pathogenicity in M. oryzae.
基金supported by the Ministry of Science and Technology(MOST)of China(2016YFA0501503 and 2019ZX09721001-004-003)the National Natural Science Foundation of China(31670136,31870127,and 81861138047)+1 种基金the Science and Technology Commission of Shanghai Municipality(19JC1416400)the State Key Laboratory of Drug Research(SIMM2003ZZ-03)。
文摘During infections,bacteria stimulate host cells to produce and release histamine,which is a key mediator of vital cellular processes in animals.However,the mechanisms underlying the bacterial cell’s ability to sense and respond to histamine are poorly understood.Herein,we show that HinK,a Lys R-type transcriptional regulator,is required to evoke responses to histamine in Pseudomonas aeruginosa,an important human pathogen.HinK directly binds to and activates the promoter of genes involved in histamine uptake and metabolism,iron acquisition,and Pseudomonas quinolone signal(PQS)biosynthesis.The transcriptional regulatory activity of HinK is induced when histamine is present,and it occurs when HinK binds with imidazole-4-acetic acid(Im AA),a histamine metabolite whose production in P.aeruginosa depends on the HinK-activated histamine uptake and utilization operon hin DAC-pa0222.Importantly,the inactivation of HinK inhibits diverse pathogenic phenotypes of P.aeruginosa.These results suggest that histamine acts as an interkingdom signal and provide insights into the mechanism used by pathogenic bacteria to exploit host regulatory signals to promote virulence.
