The Arabidopsis （Arabidopsis thaliana L.） genome encodes for four distinct classes of homeodomain leucinezipper （HD-ZIP） transcription factors （HD-ZIPI to HD-ZIPIV）, which are all organized in multi-gene familie...The Arabidopsis （Arabidopsis thaliana L.） genome encodes for four distinct classes of homeodomain leucinezipper （HD-ZIP） transcription factors （HD-ZIPI to HD-ZIPIV）, which are all organized in multi-gene families. HD-ZIP transcription factors act as sequence-specific DNA-binding proteins that are able to control the expression level of target genes. While HD-ZIPI and HD-ZIPII proteins are mainly associated with environmental responses, HD-ZIPIII and HD- ZIPIV are primarily known to act as patterning factors. Recent studies have challenged this view. It appears that several of the different HD-ZlP families interact genetically to align both morphogenesis and environmental responses, most likely by modulating phytohormone-signaling networks.展开更多
<abstract>Aim: To identify specifically expressed genes in the adult and fetal testes. Methods: A human testis cDNA microarray was established. Then the mRNA of adult and fetal testis was purified and probes wer...<abstract>Aim: To identify specifically expressed genes in the adult and fetal testes. Methods: A human testis cDNA microarray was established. Then the mRNA of adult and fetal testis was purified and probes were prepared by a reverse transcription reaction with the testis mRNA as template. The microarray was hybridized with probes of adult and fetal testes. The nucleic sequences of differentially expressed genes were determined and homologies were searched in the databases of the GenBank. Results: When hybridized with adult or fetal testis probes, the positive clones were 96.8 % and 95.4 %, respectively. Among these genes, one was a new testis-specific gene, which was named TSP1. TSP1 was highly expressed in human adult testis. The cDNA of TSP1 was 1,484 bp in length. The cDNA sequence of this clone was deposited in the Genbank (AF333098). TSP1 was also determined as Interim Gen Symbol (Unigene, No. Hs.98266). Protein analysis showed that TSP1 contained two functional domains: an N-terminal basic helix-loop-helix (bHLH) and a C-terminal leucine zipper (Zip). Homologous analysis showed that the 430 amino acid sequences deduced from the 1,293 bp open reading frame (ORF) had a homology with the human gene FLJ2509 (AK098575). TSP1 had also a sequence homology with Spz 1 protein of mouse. Expression profiles showed that TSP1 was specifically and strongly expressed in the testis. Conclusion: TSP1 is a gene highly expressed in adult testis. It may play an important role in spermatogenesis in the humans.展开更多
WRKY proteins are transcriptional regulators involved in plant responses to biotic and abiotic stresses, metabolisms, and developmental processes. In the present study, we isolated a WRKY cDNA, OsWRKY89 from a rice cD...WRKY proteins are transcriptional regulators involved in plant responses to biotic and abiotic stresses, metabolisms, and developmental processes. In the present study, we isolated a WRKY cDNA, OsWRKY89 from a rice cDNA library. The deduced polypeptide contains 263 amino acid residues with a potential leucine zipper structure in its N-terminus, sharing low identity with other known WRKY members. OsWRKY89 and three deletion derivatives from its N-terminal were expressed in high levels in Escherichia coli as a C-terminally six-histidine-tagged fusion protein, and purified by employing one-step affinity chromatography on a Ni-NTA column. The recombinant OsWRKY89 protein was found to bind specially to sequences harboring W box cis elements by using electrophoretic mobility shift assays. This binding activity was decreased significantly by deletion of the leucine zipper-like structure in the N-terminal of Os- WRKY89. Using a yeast two-hybrid assay system, we found that the leucine zipper motif of OsWRKY89 was involved in the protein-protein interaction. Further deletion to remove partial WRKY domain abolished completely the interaction between the expressed protein and the W boxes, indicating that the WRKY domain is essential to the DNA-binding. These data strongly suggest that the leucine zipper-like motif of OsWRKY89 plays a significant role in the protein-protein and DNA-protein interactions.展开更多
In previous studies, we found that EDRF2 was an erythroid differentiation related factor, whose expression was markedly upregulated during erythroid differentiation. It suggested that this factor played a role in eryt...In previous studies, we found that EDRF2 was an erythroid differentiation related factor, whose expression was markedly upregulated during erythroid differentiation. It suggested that this factor played a role in erythropoiesis. By using rapid amplification of cDNA ends technology, we cloned EDRF2 gene 5’-and 3’-cDNA ends successfully. Transfection and Northern blot analysis demonstrated that EDRF2 inhibited mRNA expression of a-globin gene, while did not regulate γ-globin gene expression. Gel shift assay confirmed that DNA-binding activity of erythroid specific transcription factors GATA-1, NF-E2 and AP1 was not affected by either forced overexpression or artificial down-regulation of EDRF2 gene in K562 cells. However, we detected that the negative regulator of expression of GATA-1 transcription factor was increased in EDRF2 overexpressed K562 cells. These results strongly suggested that EDRF2 was involved in a-globin gene expression and erythroid differentiation and served as a negative regulator of展开更多
We obtained a positive clone by screening human fetal liver cDNA library with rat C/EBP cDNA probe.The clone , designated HPS , contains 2480 base pairs , 1026 of which are coding base pairs (from No. 84 to 1109).No h...We obtained a positive clone by screening human fetal liver cDNA library with rat C/EBP cDNA probe.The clone , designated HPS , contains 2480 base pairs , 1026 of which are coding base pairs (from No. 84 to 1109).No homologous DNA sequence is found in the Gene Database (EMBL 95. 6) . The 341 amino acids encoded by HPS gene contained the leucine zipper structure at the Cterminal. They presented a high degree of homology (97%) to CIEBP throughout the DNA-binding domain and leucine repeat region(C-terminal 60 amino acids) , but in the upstream coding region , only a low degree of homology was detected to C/EBP or its related proteins , suggesting HPS is a novel member of CIEBP gene family. Southern blot analysis confirmed that HP8 gene was a single copy gene. Northern blot analysis of 14 different fetus tissues showed that HPS gene registered a high level expression in small intestine and skin , a middle level expression in adrenal ,a low level expression in liver , lung , kidney ,thyroid gland and gallbladder. Of 5 normal human adult liver tissues , only two were found to have low level HP8expression , whereas in 13 hepatoma and its surrounding nontumorous hepatic tissues , high level of HPS expression was detected in 9 hepatomas and 7 surrounding nontumorous hepatic tissues. These results suggest that HP8 gene may be a transactivator related to cell growth. A deeper research of its functions is now in progress.展开更多
Plant basic-leucine zipper （bZlP） transcription factors play important roles in many biological processes. In the present study, a bZlP gene, GmbZIP132, was cloned from soybean and its biological function under abio...Plant basic-leucine zipper （bZlP） transcription factors play important roles in many biological processes. In the present study, a bZlP gene, GmbZIP132, was cloned from soybean and its biological function under abiotic stresses was studied. The transcription of GmbZIP132 was induced by drought and high salt treatments. Among all of the organs analyzed, its expression was the highest in cotyUedon and stems. GmbZIP132 could weakly bind to the GCN4-1ike motif （GLM） （5＇-GTGAGTCAT-3＇） in yeast one-hybrid assay. Compared with wild-type （WT） Arabidopsis plants, transgenic plants overexpressing GmbZlP132 showed reduced abscisic acid sensitivity and increased water loss rate. At the stage of germination, transgenic plants were more tolerant to salt treatment than wild-type plants. The expression of some abiotic stress-related genes, such as rd29B, DREB2A, and PSCS, were upregulated in the transgenic plants. These results indicated that GmbZlP132 was an abioUc stress-related gene, and its overexpression could increase the salt tolerance of transgenic Arabidopsis plants during germination, yet no significant difference of tolerance to abiotic stresses was found between transgenic and wild type plants at the seedling stage.展开更多
Transcription factors constitute numerous signal transduction networks and play a central role in gene expression regulation. Recent studies have shown that a limited portion of transcription factors are anchored in t...Transcription factors constitute numerous signal transduction networks and play a central role in gene expression regulation. Recent studies have shown that a limited portion of transcription factors are anchored in the cellular membrane, storing as dormant forms. Upon exposure to environmental and developmental cues, these transcription factors are released from the membrane and translocated to the nucleus, where they regulate associated target genes. As this process skips both transcriptional and translational regulations, it guarantees prompt response to external and internal signals. Membrane- bound transcription factors （MTFs） undergo several unique steps that are not involved in the action of canonical nuclear transcription factors： proteolytic processing and intracellular movement. Recently, alternative splicing has also emerged as a mechanism to liberate MTFs from the cellular membranes, establishing an additional activation scheme independent of proteolytic processing. Multiple layers of MTF regulation add complexity to transcriptional regulatory scheme and ensure elaborate action of MTFs. In this review, we provide an overview of recent findings on MTFs in plants and highlight the molecular mechanisms underlying MTF liberation from cellular membranes with an emphasis on intracellular movement.展开更多
The basic leucine zipper （bZIP） transcription factors form a large gene family that is important in pathogen defense, light and stress signaling, etc. The Completed whole genome sequences of model plants Arabidopsis...The basic leucine zipper （bZIP） transcription factors form a large gene family that is important in pathogen defense, light and stress signaling, etc. The Completed whole genome sequences of model plants Arabidopsis （Arabidopsis thaliana）, rice （Oryza sativa） and poplar （Populus trichocarpa） constitute a valuable resource for genome-wide analysis and genomic comparative analysis, as they are representatives of the two major evolutionary lineages within the angiosperms： the monocotyledons and the dicotyledons. In this study, bioinformatics analysis identified 74, 89 and 88 bZIP genes respectively in Arabidopsis, rice and poplar. Moreover, a comprehensive overview of this gene family is presented, including the gene structure, phylogeny, chromosome distribution, conserved motifs. As a result, the plant bZIPs were organized into 10 subfamilies on basis of phylogenetic relationship. Gene duplication events during the family evolution history were also investigated. And it was further concluded that chromosomal/segmental duplication might have played a key role in gene expansion of bZIP gene family.展开更多
基金funded by the Deutsche Forschungsgemeinschaft, an International Reintegration Grant of the European Union, the European Research Council and the German Ministry for Agriculture
文摘The Arabidopsis （Arabidopsis thaliana L.） genome encodes for four distinct classes of homeodomain leucinezipper （HD-ZIP） transcription factors （HD-ZIPI to HD-ZIPIV）, which are all organized in multi-gene families. HD-ZIP transcription factors act as sequence-specific DNA-binding proteins that are able to control the expression level of target genes. While HD-ZIPI and HD-ZIPII proteins are mainly associated with environmental responses, HD-ZIPIII and HD- ZIPIV are primarily known to act as patterning factors. Recent studies have challenged this view. It appears that several of the different HD-ZlP families interact genetically to align both morphogenesis and environmental responses, most likely by modulating phytohormone-signaling networks.
文摘<abstract>Aim: To identify specifically expressed genes in the adult and fetal testes. Methods: A human testis cDNA microarray was established. Then the mRNA of adult and fetal testis was purified and probes were prepared by a reverse transcription reaction with the testis mRNA as template. The microarray was hybridized with probes of adult and fetal testes. The nucleic sequences of differentially expressed genes were determined and homologies were searched in the databases of the GenBank. Results: When hybridized with adult or fetal testis probes, the positive clones were 96.8 % and 95.4 %, respectively. Among these genes, one was a new testis-specific gene, which was named TSP1. TSP1 was highly expressed in human adult testis. The cDNA of TSP1 was 1,484 bp in length. The cDNA sequence of this clone was deposited in the Genbank (AF333098). TSP1 was also determined as Interim Gen Symbol (Unigene, No. Hs.98266). Protein analysis showed that TSP1 contained two functional domains: an N-terminal basic helix-loop-helix (bHLH) and a C-terminal leucine zipper (Zip). Homologous analysis showed that the 430 amino acid sequences deduced from the 1,293 bp open reading frame (ORF) had a homology with the human gene FLJ2509 (AK098575). TSP1 had also a sequence homology with Spz 1 protein of mouse. Expression profiles showed that TSP1 was specifically and strongly expressed in the testis. Conclusion: TSP1 is a gene highly expressed in adult testis. It may play an important role in spermatogenesis in the humans.
基金This work was supported by the State Basic Research and Development Plan(G200001 6203)the National Natural Science Foundation of China(Grant Nos.30370139&30471122).
文摘WRKY proteins are transcriptional regulators involved in plant responses to biotic and abiotic stresses, metabolisms, and developmental processes. In the present study, we isolated a WRKY cDNA, OsWRKY89 from a rice cDNA library. The deduced polypeptide contains 263 amino acid residues with a potential leucine zipper structure in its N-terminus, sharing low identity with other known WRKY members. OsWRKY89 and three deletion derivatives from its N-terminal were expressed in high levels in Escherichia coli as a C-terminally six-histidine-tagged fusion protein, and purified by employing one-step affinity chromatography on a Ni-NTA column. The recombinant OsWRKY89 protein was found to bind specially to sequences harboring W box cis elements by using electrophoretic mobility shift assays. This binding activity was decreased significantly by deletion of the leucine zipper-like structure in the N-terminal of Os- WRKY89. Using a yeast two-hybrid assay system, we found that the leucine zipper motif of OsWRKY89 was involved in the protein-protein interaction. Further deletion to remove partial WRKY domain abolished completely the interaction between the expressed protein and the W boxes, indicating that the WRKY domain is essential to the DNA-binding. These data strongly suggest that the leucine zipper-like motif of OsWRKY89 plays a significant role in the protein-protein and DNA-protein interactions.
文摘In previous studies, we found that EDRF2 was an erythroid differentiation related factor, whose expression was markedly upregulated during erythroid differentiation. It suggested that this factor played a role in erythropoiesis. By using rapid amplification of cDNA ends technology, we cloned EDRF2 gene 5’-and 3’-cDNA ends successfully. Transfection and Northern blot analysis demonstrated that EDRF2 inhibited mRNA expression of a-globin gene, while did not regulate γ-globin gene expression. Gel shift assay confirmed that DNA-binding activity of erythroid specific transcription factors GATA-1, NF-E2 and AP1 was not affected by either forced overexpression or artificial down-regulation of EDRF2 gene in K562 cells. However, we detected that the negative regulator of expression of GATA-1 transcription factor was increased in EDRF2 overexpressed K562 cells. These results strongly suggested that EDRF2 was involved in a-globin gene expression and erythroid differentiation and served as a negative regulator of
文摘We obtained a positive clone by screening human fetal liver cDNA library with rat C/EBP cDNA probe.The clone , designated HPS , contains 2480 base pairs , 1026 of which are coding base pairs (from No. 84 to 1109).No homologous DNA sequence is found in the Gene Database (EMBL 95. 6) . The 341 amino acids encoded by HPS gene contained the leucine zipper structure at the Cterminal. They presented a high degree of homology (97%) to CIEBP throughout the DNA-binding domain and leucine repeat region(C-terminal 60 amino acids) , but in the upstream coding region , only a low degree of homology was detected to C/EBP or its related proteins , suggesting HPS is a novel member of CIEBP gene family. Southern blot analysis confirmed that HP8 gene was a single copy gene. Northern blot analysis of 14 different fetus tissues showed that HPS gene registered a high level expression in small intestine and skin , a middle level expression in adrenal ,a low level expression in liver , lung , kidney ,thyroid gland and gallbladder. Of 5 normal human adult liver tissues , only two were found to have low level HP8expression , whereas in 13 hepatoma and its surrounding nontumorous hepatic tissues , high level of HPS expression was detected in 9 hepatomas and 7 surrounding nontumorous hepatic tissues. These results suggest that HP8 gene may be a transactivator related to cell growth. A deeper research of its functions is now in progress.
基金the National Natural Science Foundation of China (30490254)the State Key Basic Research and Development Plan of China(2004CB117200).
文摘Plant basic-leucine zipper （bZlP） transcription factors play important roles in many biological processes. In the present study, a bZlP gene, GmbZIP132, was cloned from soybean and its biological function under abiotic stresses was studied. The transcription of GmbZIP132 was induced by drought and high salt treatments. Among all of the organs analyzed, its expression was the highest in cotyUedon and stems. GmbZIP132 could weakly bind to the GCN4-1ike motif （GLM） （5＇-GTGAGTCAT-3＇） in yeast one-hybrid assay. Compared with wild-type （WT） Arabidopsis plants, transgenic plants overexpressing GmbZlP132 showed reduced abscisic acid sensitivity and increased water loss rate. At the stage of germination, transgenic plants were more tolerant to salt treatment than wild-type plants. The expression of some abiotic stress-related genes, such as rd29B, DREB2A, and PSCS, were upregulated in the transgenic plants. These results indicated that GmbZlP132 was an abioUc stress-related gene, and its overexpression could increase the salt tolerance of transgenic Arabidopsis plants during germination, yet no significant difference of tolerance to abiotic stresses was found between transgenic and wild type plants at the seedling stage.
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(NRF-2013R1A1A1004831)research funds of Chonbuk National University in 2012
文摘Transcription factors constitute numerous signal transduction networks and play a central role in gene expression regulation. Recent studies have shown that a limited portion of transcription factors are anchored in the cellular membrane, storing as dormant forms. Upon exposure to environmental and developmental cues, these transcription factors are released from the membrane and translocated to the nucleus, where they regulate associated target genes. As this process skips both transcriptional and translational regulations, it guarantees prompt response to external and internal signals. Membrane- bound transcription factors （MTFs） undergo several unique steps that are not involved in the action of canonical nuclear transcription factors： proteolytic processing and intracellular movement. Recently, alternative splicing has also emerged as a mechanism to liberate MTFs from the cellular membranes, establishing an additional activation scheme independent of proteolytic processing. Multiple layers of MTF regulation add complexity to transcriptional regulatory scheme and ensure elaborate action of MTFs. In this review, we provide an overview of recent findings on MTFs in plants and highlight the molecular mechanisms underlying MTF liberation from cellular membranes with an emphasis on intracellular movement.
文摘The basic leucine zipper （bZIP） transcription factors form a large gene family that is important in pathogen defense, light and stress signaling, etc. The Completed whole genome sequences of model plants Arabidopsis （Arabidopsis thaliana）, rice （Oryza sativa） and poplar （Populus trichocarpa） constitute a valuable resource for genome-wide analysis and genomic comparative analysis, as they are representatives of the two major evolutionary lineages within the angiosperms： the monocotyledons and the dicotyledons. In this study, bioinformatics analysis identified 74, 89 and 88 bZIP genes respectively in Arabidopsis, rice and poplar. Moreover, a comprehensive overview of this gene family is presented, including the gene structure, phylogeny, chromosome distribution, conserved motifs. As a result, the plant bZIPs were organized into 10 subfamilies on basis of phylogenetic relationship. Gene duplication events during the family evolution history were also investigated. And it was further concluded that chromosomal/segmental duplication might have played a key role in gene expansion of bZIP gene family.
