Acidithiobacillus caldus plays an important role in commercial bioleaching.To understand how NaCl stress adaptation occurs in A.caldus,we grew A.caldus strain SM-1 in media containing high NaCl concentrations.SM-1 gre...Acidithiobacillus caldus plays an important role in commercial bioleaching.To understand how NaCl stress adaptation occurs in A.caldus,we grew A.caldus strain SM-1 in media containing high NaCl concentrations.SM-1 grew at concentrations of up to 1.0-mol L^(-1)NaCl,but growth was severely inhibited at higher concentrations.Proteomic analysis showed that SM-1 used multiple strategies to respond to NaCl stress.In addition to several heatshock proteins,enzymes involved in proline biosynthesis increased under NaCl stress.In addition,two DNA-binding proteins and a third protein of unknown function(Atc_(1291)),which was subsequently identified as a putative single-stranded DNA-binding protein,were up-regulated in the presence of NaCl stress.These DNA-binding proteins might play a role in response to osmotic stress.Atc_(1291)was cloned and expressed in Escherichia coli.Surprisingly,we found that E.coli BL21/pET28a-atc_(1291)grew to higher cell densities than E.coli BL21/pET28a,regardless of NaCI stress.Homologs to Atc_(1291)were identified in several groups of Proleohacleria.The role of Atc_(1291)in enhancing cell growth needs further investigation.展开更多
Sarcopterygians is an important vertebrate clade that includes crossopterygians and tetrapods.Crossopterygians are lobe-finned fish that include lungfish and coelacanths.Tetrapods include amphibians,reptiles,avians an...Sarcopterygians is an important vertebrate clade that includes crossopterygians and tetrapods.Crossopterygians are lobe-finned fish that include lungfish and coelacanths.Tetrapods include amphibians,reptiles,avians and mammals.To compare the interferon regulatory factor 1 (irf-1) gene structure and to explore phylogenetic relationships among sarcopterygians,we cloned the cDNA sequence of irf-1 from lungfish and compared it with irf-1 orthologs in other sarcopterygian species.The lungfish is a primitive sarcopterygian that occupies a very important position in vertebrate phylogeny.Interferon regulatory factors (IRFs) are a family of proteins involved in innate immunity.To date,11 IRF family members have been reported.All IRFs share homology in the first 115 amino acids,which encompasses a DNA binding domain containing a characteristic repeat of 5 tryptophan residues separated by 10-18 amino acids.IRF-1 and IRF-2 were the first members of this family to be reported and they have a very important role in innate immunity.However,studies of the irf-1 and irf-2 genes are mostly confined to mammals;very few non-mammalian irf-1 genes have been reported.Consistent with the irf-1 gene sequences already published,the first 345 nucleotides of lungfish irf-1 are highly conserved.At the carboxyl terminal a C-terminal transactivating region motif and an interferon associated domain (IAD2) were identified.417 million years separate the present from the closest common ancestor of lungfish and tetrapods;however,the irf-1 genes among sarcopterygians are highly conserved and have very obvious phylogenetic relationships.Also the interrelationship tree of sarcopterygians,based on IRF-1 amino acid sequences,is identical with trees produced using other data,such as morphological characteristics or mitochondrial gene sequences.展开更多
基金supported by the National High Technology Research and Development Program of China(2012AA061501)the National Key Basic Research and Development Program of China(2010CB630903)the National Natural Sciences Foundation of China(31171234)
文摘Acidithiobacillus caldus plays an important role in commercial bioleaching.To understand how NaCl stress adaptation occurs in A.caldus,we grew A.caldus strain SM-1 in media containing high NaCl concentrations.SM-1 grew at concentrations of up to 1.0-mol L^(-1)NaCl,but growth was severely inhibited at higher concentrations.Proteomic analysis showed that SM-1 used multiple strategies to respond to NaCl stress.In addition to several heatshock proteins,enzymes involved in proline biosynthesis increased under NaCl stress.In addition,two DNA-binding proteins and a third protein of unknown function(Atc_(1291)),which was subsequently identified as a putative single-stranded DNA-binding protein,were up-regulated in the presence of NaCl stress.These DNA-binding proteins might play a role in response to osmotic stress.Atc_(1291)was cloned and expressed in Escherichia coli.Surprisingly,we found that E.coli BL21/pET28a-atc_(1291)grew to higher cell densities than E.coli BL21/pET28a,regardless of NaCI stress.Homologs to Atc_(1291)were identified in several groups of Proleohacleria.The role of Atc_(1291)in enhancing cell growth needs further investigation.
基金supported by the National Key Basic Research Program of China (HCV2009CB522500)
文摘Sarcopterygians is an important vertebrate clade that includes crossopterygians and tetrapods.Crossopterygians are lobe-finned fish that include lungfish and coelacanths.Tetrapods include amphibians,reptiles,avians and mammals.To compare the interferon regulatory factor 1 (irf-1) gene structure and to explore phylogenetic relationships among sarcopterygians,we cloned the cDNA sequence of irf-1 from lungfish and compared it with irf-1 orthologs in other sarcopterygian species.The lungfish is a primitive sarcopterygian that occupies a very important position in vertebrate phylogeny.Interferon regulatory factors (IRFs) are a family of proteins involved in innate immunity.To date,11 IRF family members have been reported.All IRFs share homology in the first 115 amino acids,which encompasses a DNA binding domain containing a characteristic repeat of 5 tryptophan residues separated by 10-18 amino acids.IRF-1 and IRF-2 were the first members of this family to be reported and they have a very important role in innate immunity.However,studies of the irf-1 and irf-2 genes are mostly confined to mammals;very few non-mammalian irf-1 genes have been reported.Consistent with the irf-1 gene sequences already published,the first 345 nucleotides of lungfish irf-1 are highly conserved.At the carboxyl terminal a C-terminal transactivating region motif and an interferon associated domain (IAD2) were identified.417 million years separate the present from the closest common ancestor of lungfish and tetrapods;however,the irf-1 genes among sarcopterygians are highly conserved and have very obvious phylogenetic relationships.Also the interrelationship tree of sarcopterygians,based on IRF-1 amino acid sequences,is identical with trees produced using other data,such as morphological characteristics or mitochondrial gene sequences.
