Transcription factors play key roles in plant development and stress responses through their interaction with cis-elements and/or other transcription factors. Homeodomain associated leucine zipper proteins (HD-Zip) co...Transcription factors play key roles in plant development and stress responses through their interaction with cis-elements and/or other transcription factors. Homeodomain associated leucine zipper proteins (HD-Zip) constitute a family of transcription factors that are characterized by the presence of a DNA-binding domain closely linked with leucine zipper motif functioning in dimer formation. This type of association is unique to plants and considered as an excellent candidate to activate developmental responses to altering environmental conditions. Cotton is the most important fiber plant with a lot of local and commercial uses in the world. HD-Zip proteins not only have key roles in different stages of vascular and inter-fascicular fiber differentiation of cotton but also are suggested to have an important role against abiotic stress that is one of the key factors limiting cotton productivity. Plants have developed various strategies to manage stress conditions through a combination of metabolic, physiological and morphological adaptations. These adaptive changes rely largely on alterations in gene expression. Therefore, transcriptional regulators play a crucial role in stress tolerance. Being a transcription factor HD-Zip might be a useful target for genetic engineering to generate multiple stress tolerance in susceptible plants. In the following chapter, we discussed how the HD-Zip proteins would play a useful role for cotton development both in fiber production and stress adaptation.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 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
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
Oligodencrocytes（OLs） are the main glial cells of the central nervous system involved in myelination of axons. In multiple sclerosis（MS）, there is an imbalance between demyelination and remyelination processes, th...Oligodencrocytes（OLs） are the main glial cells of the central nervous system involved in myelination of axons. In multiple sclerosis（MS）, there is an imbalance between demyelination and remyelination processes, the last one performed by oligodendrocyte progenitor cells（OPCs） and OLs, resulting into a permanent demyelination, axonal damage and neuronal loss. In MS lesions, astrocytes and microglias play an important part in permeabilization of blood-brain barrier and initiation of OPCs proliferation. Migration and differentiation of OPCs are influenced by various factors and the process is finalized by insufficient acummulation of OLs into the MS lesion. In relation to all these processes, the author will discuss the potential targets for remyelination strategies.展开更多
文摘Transcription factors play key roles in plant development and stress responses through their interaction with cis-elements and/or other transcription factors. Homeodomain associated leucine zipper proteins (HD-Zip) constitute a family of transcription factors that are characterized by the presence of a DNA-binding domain closely linked with leucine zipper motif functioning in dimer formation. This type of association is unique to plants and considered as an excellent candidate to activate developmental responses to altering environmental conditions. Cotton is the most important fiber plant with a lot of local and commercial uses in the world. HD-Zip proteins not only have key roles in different stages of vascular and inter-fascicular fiber differentiation of cotton but also are suggested to have an important role against abiotic stress that is one of the key factors limiting cotton productivity. Plants have developed various strategies to manage stress conditions through a combination of metabolic, physiological and morphological adaptations. These adaptive changes rely largely on alterations in gene expression. Therefore, transcriptional regulators play a crucial role in stress tolerance. Being a transcription factor HD-Zip might be a useful target for genetic engineering to generate multiple stress tolerance in susceptible plants. In the following chapter, we discussed how the HD-Zip proteins would play a useful role for cotton development both in fiber production and stress adaptation.
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.
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.
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Oligodencrocytes（OLs） are the main glial cells of the central nervous system involved in myelination of axons. In multiple sclerosis（MS）, there is an imbalance between demyelination and remyelination processes, the last one performed by oligodendrocyte progenitor cells（OPCs） and OLs, resulting into a permanent demyelination, axonal damage and neuronal loss. In MS lesions, astrocytes and microglias play an important part in permeabilization of blood-brain barrier and initiation of OPCs proliferation. Migration and differentiation of OPCs are influenced by various factors and the process is finalized by insufficient acummulation of OLs into the MS lesion. In relation to all these processes, the author will discuss the potential targets for remyelination strategies.
