Ambient light has profound effects on early seedling de-etiolation through red and far-red light-absorbing phytochromes and blue and UV-A light-absorbing cryptochromes. Subsequent integration of various light signal t...Ambient light has profound effects on early seedling de-etiolation through red and far-red light-absorbing phytochromes and blue and UV-A light-absorbing cryptochromes. Subsequent integration of various light signal trans- duction pathways leads to changes in gene expression and morphogenic responses. Here, we report the isolation of a new Arabidopsis light-signaling component, HYPOSENSITIVE TO LIGHT or HTL. Both htl-1 and htl-2 alleles displayed a long hypocotyl phenotype under red, far-red, and blue light, whereas overexpression of HTL caused a short hypocotyl pheno- type under similar light conditions. The mutants also showed other photomorphogenic defects such as elongated petioles, retarded cotyledon and leaf expansion, reduced accumulation of chlorophyll and anthocyanin pigments, and attenuated expression of light-responsive CHLOROPHYLL A/B BINDING PROTEIN 3 and CHALCONE SYNTHASE genes. HTL belongs to an alpha/beta fold protein family and is localized strongly in the nucleus and weakly in the cytosol. The expression of HTL was strongly induced by light of various wavelengths and this light induction was impaired in elongated hypocotyl 5. HY5 directly bound to both a C/G-box and a G-box in the HTL promoter but with a greater affinity toward the C/G-box. HTL, therefore, represents a new signaling step downstream of HY5 in phy- and cry-mediated de-etiolation responses.展开更多
A general and elementary protein folding step was described in a previous article. Energy conservation during this folding step yielded an equation with remarkable solutions over the field of rational numbers. Sets of...A general and elementary protein folding step was described in a previous article. Energy conservation during this folding step yielded an equation with remarkable solutions over the field of rational numbers. Sets of sequences optimized for folding were derived. In this work, a geometrical analysis of protein beta-sheet backbone structures allows the definition of positions of topological interest. They correspond to amino acids’ alpha carbons located on a unique axis crossing all beta-sheet’s strands or at proximity of this axis defined here. These positions of topological interest are shown to be highly correlated with the absence of sequences optimized for folding. Applications in protein structure prediction for the quality assessment of structural models are envisioned.展开更多
The pathological implication of amyloid precursor protein(APP)in Alzheimer’s disease has been widely documented due to its involvement in the generation of amyloid-β peptide.However,the physiological functions of AP...The pathological implication of amyloid precursor protein(APP)in Alzheimer’s disease has been widely documented due to its involvement in the generation of amyloid-β peptide.However,the physiological functions of APP are still poorly understood.APP is considered a multimodal protein due to its role in a wide variety of processes,both in the embryo and in the adult brain.Specifically,APP seems to play a key role in the proliferation,differentiation and maturation of neural stem cells.In addition,APP can be processed through two canonical processing pathways,generating different functionally active fragments:soluble APP-α,soluble APP-β,amyloid-β peptide and the APP intracellular C-terminal domain.These fragments also appear to modulate various functions in neural stem cells,including the processes of proliferation,neurogenesis,gliogenesis or cell death.However,the molecular mechanisms involved in these effects are still unclear.In this review,we summarize the physiological functions of APP and its main proteolytic derivatives in neural stem cells,as well as the possible signaling pathways that could be implicated in these effects.The knowledge of these functions and signaling pathways involved in the onset or during the development of Alzheimer’s disease is essential to advance the understanding of the pathogenesis of Alzheimer’s disease,and in the search for potential therapeutic targets.展开更多
The following article has been retracted due to the investigation of complaints received against it. The Editorial Board found that the same contents have been published in another journal at the same time. The scient...The following article has been retracted due to the investigation of complaints received against it. The Editorial Board found that the same contents have been published in another journal at the same time. The scientific community takes a very strong view on this matter, and the Open Journal of Stomatology treats all unethical behavior such as plagiarism seriously. This paper published in Vol.3 No.1 32-38, 2013 has been removed from this site. Title: Elevated levels of inflammatory cytokines and high-sensitivity C-reactive protein in periodontitis patients in Kosovo: A pilot study Authors: Zana Sllamniku-Dalipi, Hasan Mehmeti, Fatmir Dragidella, Ferit Kocani, Metush Disha, Kastriot Meqa, Luljeta Begolli, Gramos展开更多
N-acetylatedα-synuclein(αSyn)has long been established as an intrinsically disordered protein associated with a dysfunctional role in Parkinson’s disease.In recent years,a physiologically relevant,higher order conf...N-acetylatedα-synuclein(αSyn)has long been established as an intrinsically disordered protein associated with a dysfunctional role in Parkinson’s disease.In recent years,a physiologically relevant,higher order conformation has been identified as a helical tetramer that is tailored by buried hydrophobic interactions and is distinctively aggregation resistant.The canonical mechanism by which the tetramer assembles remains elusive.As novel biochemical approaches,computational methods,pioneering purification platforms,and powerful imaging techniques continue to develop,puzzling information that once sparked debate as to the veracity of the tetramer has now shed light upon this new counterpart inαSyn neurobiology.Nuclear magnetic resonance and computational studies on multimericαSyn structure have revealed that the protein folding propensity is controlled by small energy barriers that enable large scale reconfiguration.Alternatively,familial mutations ablate tetramerization and reconfigure polymorphic fibrillization.In this review,we will discuss the dynamic landscape ofαSyn quaternary structure with a focus on the tetrameric conformation.展开更多
Antimicrobial peptides are promising therapeutic agents in view of increasing resistance to conventional antibiotics. Antimicrobial peptides usually fold in α-helical, β-sheet, and extended/random-coil structures. T...Antimicrobial peptides are promising therapeutic agents in view of increasing resistance to conventional antibiotics. Antimicrobial peptides usually fold in α-helical, β-sheet, and extended/random-coil structures. The α-helical antimicrobial peptides are often unstructured in aqueous solution but become structured on bacterial membrane. The α-helical structure allows the partitioning into bacterial membrane. Therefore it is important to understand the mechanism of unfolding and refolding of α-helical structure in antimicrobial peptides. It is not very easy to obverse and study the process of unfolding and refolding of α-helical antimicrobial peptides because of their rapidity. Therefore, molecular simulation provides a way to observe and explain this phenomenon. Plantaricin A is a 26 amino-acid antimicrobial pheromone peptide and can spontaneously unfold and refold under physiological condition. This study demonstrated the unfolding and refolding of plantaricin A by means of molecular simulation, and its mechanism was discussed with its implication to the Levinthal paradox.展开更多
基金This work was supported by the National Science Foundation，by the Plant Biological Sciences Doctoral Dissertation Fellowship and Summer Fellowship from the University of Minnesota
文摘Ambient light has profound effects on early seedling de-etiolation through red and far-red light-absorbing phytochromes and blue and UV-A light-absorbing cryptochromes. Subsequent integration of various light signal trans- duction pathways leads to changes in gene expression and morphogenic responses. Here, we report the isolation of a new Arabidopsis light-signaling component, HYPOSENSITIVE TO LIGHT or HTL. Both htl-1 and htl-2 alleles displayed a long hypocotyl phenotype under red, far-red, and blue light, whereas overexpression of HTL caused a short hypocotyl pheno- type under similar light conditions. The mutants also showed other photomorphogenic defects such as elongated petioles, retarded cotyledon and leaf expansion, reduced accumulation of chlorophyll and anthocyanin pigments, and attenuated expression of light-responsive CHLOROPHYLL A/B BINDING PROTEIN 3 and CHALCONE SYNTHASE genes. HTL belongs to an alpha/beta fold protein family and is localized strongly in the nucleus and weakly in the cytosol. The expression of HTL was strongly induced by light of various wavelengths and this light induction was impaired in elongated hypocotyl 5. HY5 directly bound to both a C/G-box and a G-box in the HTL promoter but with a greater affinity toward the C/G-box. HTL, therefore, represents a new signaling step downstream of HY5 in phy- and cry-mediated de-etiolation responses.
文摘A general and elementary protein folding step was described in a previous article. Energy conservation during this folding step yielded an equation with remarkable solutions over the field of rational numbers. Sets of sequences optimized for folding were derived. In this work, a geometrical analysis of protein beta-sheet backbone structures allows the definition of positions of topological interest. They correspond to amino acids’ alpha carbons located on a unique axis crossing all beta-sheet’s strands or at proximity of this axis defined here. These positions of topological interest are shown to be highly correlated with the absence of sequences optimized for folding. Applications in protein structure prediction for the quality assessment of structural models are envisioned.
基金supported by grants from the Ministerio de Ciencia e Innovación-Instituto de Salud Carlos Ⅲ(PI-10/00291 and MPY1412/09)Ministerio de Economía y Competitividad(SAF2015-71140-R)+2 种基金Comunidad de Madrid(Neurostem-Comunidad de Madrid consortium S2010/BMD-2336)supported by grants from Plan de Empleo Juvenil-Ministerio de Economía y Competitividad
文摘The pathological implication of amyloid precursor protein(APP)in Alzheimer’s disease has been widely documented due to its involvement in the generation of amyloid-β peptide.However,the physiological functions of APP are still poorly understood.APP is considered a multimodal protein due to its role in a wide variety of processes,both in the embryo and in the adult brain.Specifically,APP seems to play a key role in the proliferation,differentiation and maturation of neural stem cells.In addition,APP can be processed through two canonical processing pathways,generating different functionally active fragments:soluble APP-α,soluble APP-β,amyloid-β peptide and the APP intracellular C-terminal domain.These fragments also appear to modulate various functions in neural stem cells,including the processes of proliferation,neurogenesis,gliogenesis or cell death.However,the molecular mechanisms involved in these effects are still unclear.In this review,we summarize the physiological functions of APP and its main proteolytic derivatives in neural stem cells,as well as the possible signaling pathways that could be implicated in these effects.The knowledge of these functions and signaling pathways involved in the onset or during the development of Alzheimer’s disease is essential to advance the understanding of the pathogenesis of Alzheimer’s disease,and in the search for potential therapeutic targets.
文摘The following article has been retracted due to the investigation of complaints received against it. The Editorial Board found that the same contents have been published in another journal at the same time. The scientific community takes a very strong view on this matter, and the Open Journal of Stomatology treats all unethical behavior such as plagiarism seriously. This paper published in Vol.3 No.1 32-38, 2013 has been removed from this site. Title: Elevated levels of inflammatory cytokines and high-sensitivity C-reactive protein in periodontitis patients in Kosovo: A pilot study Authors: Zana Sllamniku-Dalipi, Hasan Mehmeti, Fatmir Dragidella, Ferit Kocani, Metush Disha, Kastriot Meqa, Luljeta Begolli, Gramos
基金supported in part by Award No.18-7(to HRL)from the Commonwealth of Virginia’s Alzheimer’s and Related Diseases Research Award Fund,administered by the Virginia Center on Aging
文摘N-acetylatedα-synuclein(αSyn)has long been established as an intrinsically disordered protein associated with a dysfunctional role in Parkinson’s disease.In recent years,a physiologically relevant,higher order conformation has been identified as a helical tetramer that is tailored by buried hydrophobic interactions and is distinctively aggregation resistant.The canonical mechanism by which the tetramer assembles remains elusive.As novel biochemical approaches,computational methods,pioneering purification platforms,and powerful imaging techniques continue to develop,puzzling information that once sparked debate as to the veracity of the tetramer has now shed light upon this new counterpart inαSyn neurobiology.Nuclear magnetic resonance and computational studies on multimericαSyn structure have revealed that the protein folding propensity is controlled by small energy barriers that enable large scale reconfiguration.Alternatively,familial mutations ablate tetramerization and reconfigure polymorphic fibrillization.In this review,we will discuss the dynamic landscape ofαSyn quaternary structure with a focus on the tetrameric conformation.
文摘Antimicrobial peptides are promising therapeutic agents in view of increasing resistance to conventional antibiotics. Antimicrobial peptides usually fold in α-helical, β-sheet, and extended/random-coil structures. The α-helical antimicrobial peptides are often unstructured in aqueous solution but become structured on bacterial membrane. The α-helical structure allows the partitioning into bacterial membrane. Therefore it is important to understand the mechanism of unfolding and refolding of α-helical structure in antimicrobial peptides. It is not very easy to obverse and study the process of unfolding and refolding of α-helical antimicrobial peptides because of their rapidity. Therefore, molecular simulation provides a way to observe and explain this phenomenon. Plantaricin A is a 26 amino-acid antimicrobial pheromone peptide and can spontaneously unfold and refold under physiological condition. This study demonstrated the unfolding and refolding of plantaricin A by means of molecular simulation, and its mechanism was discussed with its implication to the Levinthal paradox.
