Dickeya fangzhongdai, the causal agent of bleeding canker of pear, is a new member of the Dickeya genus and the only one that infects woody plants. Recent studies have reclassified several Dickeya isolates as D. fangz...Dickeya fangzhongdai, the causal agent of bleeding canker of pear, is a new member of the Dickeya genus and the only one that infects woody plants. Recent studies have reclassified several Dickeya isolates as D. fangzhongdai, which were isolated from various environments, including water, Phalaenopsis sp. and Aglaonema sp. To provide genomic characterization of D. fangzhongdai isolates from pear, the genomes of D. fangzhongdai strain JS5(=China General Microbiological Culture Collection Center, CGMCC 1.15464 ~T=DSM 101947 ~T), along with two other isolates, LN1 and QZH3, were sequenced and compared to those of other Dickeya spp. Homology greater than 99% was observed among three D. fangzhongdai strains. Plasmid, type IV secretion system(T4 SS) and type IV pili(TFPs) were found in genomes of D. fangzhongdai isolates. Comparative analysis of the type Ⅲ secretion systems(T3 SS), type Ⅲ secretion effectors(T3 SE), plant cell wall degradation enzymes(PCWDE) and membrane transport proteins of Dickeya spp. showed some differences which might reflect the variations of virulence, phylogenetic and phenotypic characteristics of Dickeya spp. In addition, deletion mutant of TFP in D. fangzhongdai JS5 showed no twitching motility and reduced virulence and biofilm formation. The fingdings of the distinctive plasmid, T4 SS and TFPs, as well as the differences of T3 SE, PCWDE and membrane transport proteins make D. fangzhongdai isolates unique. These results also suggested that acquisition of virulence genes by horizontal gene transfer might play some role in the genetic variation of D. fangzhongdai.展开更多
The regenerating islet-derived members (Reg ),a group of small secretory proteins,which are involved in cell proliferation or differentiation in digestive organs,are upregulated in several gastrointestinal cancers,fun...The regenerating islet-derived members (Reg ),a group of small secretory proteins,which are involved in cell proliferation or differentiation in digestive organs,are upregulated in several gastrointestinal cancers,functioning as trophic or antiapoptotic factors.Regenerating islet-derived type Ⅳ (RegⅣ ),a member of the Reg gene family,has been reported to be overexpressed in gastroenterological cancers.RegIV overexpression in tumor cells has been associated with carcinogenesis,cell growth,survival and resistance to apoptosis.Cancer tissue expressing RegⅣ is generally associated with more malignant characteristics than that without such expression,and RegⅣ is considered a novel prognostic factor as well as diagnostic marker in some gastroenterological cancers.We previously investigated the expression levels of RegⅣ mRNA of 202 surgical colorectal cancer specimens with quantitative real-time reverse-transcriptase polymerase chain reaction and reported that a higher level of RegⅣ gene expression was a significant independent predictor of colorectal cancer.The biologic functions of RegⅣ protein in cancer tissue,associated with carcinogenesis,antiapoptosis and invasiveness,are being elucidated by molecular investigations using transfection techniques or neutralizing antibodies of RegⅣ,and the feasibility of antibody therapy targeting RegⅣ is being assessed.These studies may lead to novel therapeutic strategies for gastroenterological cancers expressing RegⅣ .This review article summarizes the current information related to biological functions as well as clinical importance of RegⅣ gene to clarify the significance of RegⅣ expression in gastroenterological cancers.展开更多
基金supported by the 111 International Cooperation Grant 2.0(BP0719029)to Nanjing Agricultural University,China,from the Chinese government and Canadian Interdepartmental funding of Genomics Research and Development Initiatives(GRDI)。
文摘Dickeya fangzhongdai, the causal agent of bleeding canker of pear, is a new member of the Dickeya genus and the only one that infects woody plants. Recent studies have reclassified several Dickeya isolates as D. fangzhongdai, which were isolated from various environments, including water, Phalaenopsis sp. and Aglaonema sp. To provide genomic characterization of D. fangzhongdai isolates from pear, the genomes of D. fangzhongdai strain JS5(=China General Microbiological Culture Collection Center, CGMCC 1.15464 ~T=DSM 101947 ~T), along with two other isolates, LN1 and QZH3, were sequenced and compared to those of other Dickeya spp. Homology greater than 99% was observed among three D. fangzhongdai strains. Plasmid, type IV secretion system(T4 SS) and type IV pili(TFPs) were found in genomes of D. fangzhongdai isolates. Comparative analysis of the type Ⅲ secretion systems(T3 SS), type Ⅲ secretion effectors(T3 SE), plant cell wall degradation enzymes(PCWDE) and membrane transport proteins of Dickeya spp. showed some differences which might reflect the variations of virulence, phylogenetic and phenotypic characteristics of Dickeya spp. In addition, deletion mutant of TFP in D. fangzhongdai JS5 showed no twitching motility and reduced virulence and biofilm formation. The fingdings of the distinctive plasmid, T4 SS and TFPs, as well as the differences of T3 SE, PCWDE and membrane transport proteins make D. fangzhongdai isolates unique. These results also suggested that acquisition of virulence genes by horizontal gene transfer might play some role in the genetic variation of D. fangzhongdai.
文摘The regenerating islet-derived members (Reg ),a group of small secretory proteins,which are involved in cell proliferation or differentiation in digestive organs,are upregulated in several gastrointestinal cancers,functioning as trophic or antiapoptotic factors.Regenerating islet-derived type Ⅳ (RegⅣ ),a member of the Reg gene family,has been reported to be overexpressed in gastroenterological cancers.RegIV overexpression in tumor cells has been associated with carcinogenesis,cell growth,survival and resistance to apoptosis.Cancer tissue expressing RegⅣ is generally associated with more malignant characteristics than that without such expression,and RegⅣ is considered a novel prognostic factor as well as diagnostic marker in some gastroenterological cancers.We previously investigated the expression levels of RegⅣ mRNA of 202 surgical colorectal cancer specimens with quantitative real-time reverse-transcriptase polymerase chain reaction and reported that a higher level of RegⅣ gene expression was a significant independent predictor of colorectal cancer.The biologic functions of RegⅣ protein in cancer tissue,associated with carcinogenesis,antiapoptosis and invasiveness,are being elucidated by molecular investigations using transfection techniques or neutralizing antibodies of RegⅣ,and the feasibility of antibody therapy targeting RegⅣ is being assessed.These studies may lead to novel therapeutic strategies for gastroenterological cancers expressing RegⅣ .This review article summarizes the current information related to biological functions as well as clinical importance of RegⅣ gene to clarify the significance of RegⅣ expression in gastroenterological cancers.
