Plasmodium (P.) falciparum is a pathogen that causes severe forms of malaria. Protein interactions have been shown to occur between P. falciparum and human erythrocytes in human blood. The Band 3 Anion Transporter (B3...Plasmodium (P.) falciparum is a pathogen that causes severe forms of malaria. Protein interactions have been shown to occur between P. falciparum and human erythrocytes in human blood. The Band 3 Anion Transporter (B3AT) protein is considered the main invasive pathway for the parasite in erythrocytes that causes clinical symptoms for malaria in humans. The interactions between P. falciparum parasites and erythrocytes along this receptor have previously been explored. Short linear motifs (SLIMs) are short linear mediator sequences that involve several biological processes, acting as mediators of protein interactions identifiable by computational tools such as SLiMFinder. For a given protein, the identification of SLIMs allows predicting its interactors. Using the SLIMs approach, protein-protein interaction network analyses between P. falciparum and its human host, were used to identify a tryptophan-rich protein, A5K5E5_PLAVS as an essential interactor of B3AT. To better understand the interaction mechanism, a guided protein-protein docking approach based on SLIM motifs was performed for human B3AT and A5K5E5_PLAVS. The highlights of this important interaction between P. falciparum and its human host have the potential to pave the way to identify new therapeutic candidates.展开更多
Spinal cord injury involves non-reversible damage to the central nervous system that is characterized by limited regenerative capacity and secondary inflammatory damage.The expression of the C-C motif chemokine ligand...Spinal cord injury involves non-reversible damage to the central nervous system that is characterized by limited regenerative capacity and secondary inflammatory damage.The expression of the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis exhibits significant differences before and after injury.Recent studies have revealed that the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis is closely associated with secondary inflammatory responses and the recruitment of immune cells following spinal cord injury,suggesting that this axis is a novel target and regulatory control point for treatment.This review comprehensively examines the therapeutic strategies targeting the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis,along with the regenerative and repair mechanisms linking the axis to spinal cord injury.Additionally,we summarize the upstream and downstream inflammatory signaling pathways associated with spinal cord injury and the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis.This review primarily elaborates on therapeutic strategies that target the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis and the latest progress of research on antagonistic drugs,along with the approaches used to exploit new therapeutic targets within the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis and the development of targeted drugs.Nevertheless,there are presently no clinical studies relating to spinal cord injury that are focusing on the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis.This review aims to provide new ideas and therapeutic strategies for the future treatment of spinal cord injury.展开更多
Interconnection of all things challenges the traditional communication methods,and Semantic Communication and Computing(SCC)will become new solutions.It is a challenging task to accurately detect,extract,and represent...Interconnection of all things challenges the traditional communication methods,and Semantic Communication and Computing(SCC)will become new solutions.It is a challenging task to accurately detect,extract,and represent semantic information in the research of SCC-based networks.In previous research,researchers usually use convolution to extract the feature information of a graph and perform the corresponding task of node classification.However,the content of semantic information is quite complex.Although graph convolutional neural networks provide an effective solution for node classification tasks,due to their limitations in representing multiple relational patterns and not recognizing and analyzing higher-order local structures,the extracted feature information is subject to varying degrees of loss.Therefore,this paper extends from a single-layer topology network to a multi-layer heterogeneous topology network.The Bidirectional Encoder Representations from Transformers(BERT)training word vector is introduced to extract the semantic features in the network,and the existing graph neural network is improved by combining the higher-order local feature module of the network model representation network.A multi-layer network embedding algorithm on SCC-based networks with motifs is proposed to complete the task of end-to-end node classification.We verify the effectiveness of the algorithm on a real multi-layer heterogeneous network.展开更多
The image of Mulan is well known to the public as an important symbol in the dissemination of Chinese excellent traditional culture.This paper aims to summarise the mother-title from traditional canonical texts,to exp...The image of Mulan is well known to the public as an important symbol in the dissemination of Chinese excellent traditional culture.This paper aims to summarise the mother-title from traditional canonical texts,to explore the content and value of sustainable IP development,and to study a large number of derivatives with the image of Mulan as the mother-title,based on the wide circulation of the prototype of the mother-title“The Poem of Mulan”(木兰辞)and the positive values conveyed by the content.Through the processing and imagination of scholars and writers on the mother text in the past generations,the image of Mulan has gradually formed a relatively stable cultural communication theme in the process of dissemination in China’s historical period,and many adaptations with international influence based on the mother title of Mulan have emerged in the foreign dissemination,so through the combing and summarisation of the textual works of various periods both at home and abroad,we will dig out the textual transmission of the mother title of Mulan,which is representative of the mother title of China’s excellent traditional culture,and the development of the Chinese spiritual core.The Development of the Chinese Spiritual Kernel.This paper adopts research methods such as documentary evidence method and discourse analysis to show the textual flow of Mulan’s parent theme in a more diversified form.展开更多
This editorial summarizes the latest literature on the roles of neuronal PAS domain protein 2 and KN motif/ankyrin repeat domain 1 in type 2 diabetes(T2D).We highlight their involvement inβ-cell dysfunction,explore t...This editorial summarizes the latest literature on the roles of neuronal PAS domain protein 2 and KN motif/ankyrin repeat domain 1 in type 2 diabetes(T2D).We highlight their involvement inβ-cell dysfunction,explore their potential as therapeutic targets,and discuss the implications for new treatment strategies.We offer valuable insights into relevant gene regulation and cellular mechanisms relevant for the targeted management of T2D.展开更多
社区搜索的目标是从数据图中得到包含查询顶点的紧密子图,在社会学、生物学等领域有着广泛应用。针对现有基于子图连通性的社区模型的基础连通结构都是完全连通图,无法满足实际应用中用户对社区结构多样性的需求的问题,提出一种基于moti...社区搜索的目标是从数据图中得到包含查询顶点的紧密子图,在社会学、生物学等领域有着广泛应用。针对现有基于子图连通性的社区模型的基础连通结构都是完全连通图,无法满足实际应用中用户对社区结构多样性的需求的问题,提出一种基于motif连通性的社区搜索方法,其中包括基于motif连通性的社区(MCC)模型以及两个相应的社区搜索算法——MPCS(Motif-Processed Community Search)算法和基于MP-index的社区搜索算法。MCC模型可以协助用户自由指定社区的基础连通结构,MPCS算法可以用来解决MCC的搜索问题。此外,提出两个分别针对motif实例搜索过程及所属社区判断过程的剪枝优化技术。最后,设计了MP-index以避免社区搜索过程中的冗余遍历操作。在多个真实数据集上进行实验的结果表明:剪枝优化可以使MPCS算法的耗时减少60%~85%,而基于MP-index的社区搜索算法相较于加入剪枝优化的MPCS算法,效率提升普遍达到了2~3个数量级。可见,所提方法在商品推荐和社交网络等问题上有着实际应用价值。展开更多
软件动态胎记技术是实现混淆对抗的软件抄袭检测的有效手段之一.然而,多线程程序中线程交织的不确定性对其造成了不可忽视的影响;极端情况下,传统动态胎记技术甚至会判定同一个程序与其自身不存在抄袭关系.对此,提出从多线程程序在同一...软件动态胎记技术是实现混淆对抗的软件抄袭检测的有效手段之一.然而,多线程程序中线程交织的不确定性对其造成了不可忽视的影响;极端情况下,传统动态胎记技术甚至会判定同一个程序与其自身不存在抄袭关系.对此,提出从多线程程序在同一输入下的多条执行轨迹中进行相似部分的识别,并从中抽象出不易受线程交织影响的行为motifs来实现多线程程序的抄袭检测.该方法捕捉程序的动态执行轨迹,经过轨迹修剪、gram匹配以及扩展和抽象,从中提取motifs胎记建模多线程程序的行为;最终,通过衡量motifs胎记的相似性实现程序间潜在抄袭的判定.在一个包含234个不同版本多线程程序的公共数据集上开展的实验表明,motifs胎记是一种可靠的线程感知胎记方法,不仅可有效对抗当下主流的代码混淆技术,相比现有的2种多线程程序抄袭检测方法TreSB(thread-related system call birthmark)和TOB(thread-oblivious birthmark),也体现出更优秀的检测能力.展开更多
A cyclic bimetallic metal-organic complex [Zn(C)(H-fmpdc)(H2O)]2·2H2O (fmpdc = 4-(furan-2-yl)-2,6-dimethylpyridine-3,5-dicarboxylate) was synthesized and characterized by single-crystal X-ray analysis. ...A cyclic bimetallic metal-organic complex [Zn(C)(H-fmpdc)(H2O)]2·2H2O (fmpdc = 4-(furan-2-yl)-2,6-dimethylpyridine-3,5-dicarboxylate) was synthesized and characterized by single-crystal X-ray analysis. The compound crystallizes in orthorhombic, space group Pbca with a = 12.905(2), b = 14.774(3), c = 16.833(3)A, V= 3029.4(10)A^3 Z = 4, Dc = 1.644 g/cm^3, F(000) = 1616, R = 0.0347 and wR = 0.0956 (I 〉 2σ(I)). There exist diverse supramolecular motifs (1-D, 2-D and 3-D) from distinct hydrogen bonds in the crystal structure of the title compound. The furanyl group has obvious contribution to the red-shift in the photoluminescent spectrum of the H2fmpdc ligand. The title compound 1 shows strong photoluminescence with emission maximum at 2 = 402 nm (λex.max = 367 nm).展开更多
In this editorial preface, I briefly r eview cancer bioinformatics and introduce the four articles in this special issue highlighting important applications of the field: detection of chromatin states; detection of SN...In this editorial preface, I briefly r eview cancer bioinformatics and introduce the four articles in this special issue highlighting important applications of the field: detection of chromatin states; detection of SNP- containing motifs and association with transcription factor-binding sites; improvements in functional enrichment modules; and gene association studies on aging and cancer. We expect this issue to provide bioinformatics scientists, cancer biologists, and clinical doctors with a better understanding of how cancer bioinformatics can be used to identify candidate biomarkers and targets and to conduct functional analysis.展开更多
Recently, self-sustained oscillatory genetic regulatory networks (GRNs) have attracted significant attention in the biological field. Given a GRN, it is important to anticipate whether the network could generate osc...Recently, self-sustained oscillatory genetic regulatory networks (GRNs) have attracted significant attention in the biological field. Given a GRN, it is important to anticipate whether the network could generate oscillation with proper parameters, and what the key ingredients for the oscillation are. In this paper the ranges of some function-related parameters which are favorable to sustained oscillations are considered. In particular, some oscillatory motifs appearing with high-frequency in most of the oscillatory GRNs are observed. Moreover, there are some anti-oscillatory motifs which have a strong oscillation repressing effect. Some conclusions analyzing these motif effects and constructing oscillatory GRNs are provided.展开更多
The 2009 H1N1 influenza pandemic has attracted worldwide attention. The new virus first emerged in Mexico in April, 2009 was identified as a unique combination of a triple- reassortant swine influenza A virus, compose...The 2009 H1N1 influenza pandemic has attracted worldwide attention. The new virus first emerged in Mexico in April, 2009 was identified as a unique combination of a triple- reassortant swine influenza A virus, composed of genetic information from pigs, hu- mans, birds, and a Eurasian swine influenza virus. Several recent studies on the 2009 H1N1 virus util-ized small datasets to conduct analysis. With new sequences available up to date, we were able to extend the previous research in three areas. The first was finding two networks of co-mutations that may po-tentially affect the current flu-drug binding sites on neuraminidase (NA), one of the two surface proteins of flu virus. The second was discovering a special stalk motif, which was dominant in the H5N1 strains in the past, in the 2009 H1N1 strains for the first time. Due to the high virulence of this motif, the second finding is significant in our current research on 2009 H1N1. The third was updating the phylogenetic an- alysis of current NA sequences of 2009 H1N1 and H5N1, which demonstrated that, in clear contrast to previous findings, the N1 sequences in 2009 are di-verse enough to cover different major branches of the phylogenetic tree of those in previous years. As the novel influenza A H1N1 virus continues to spread globally, our results highlighted the importance of performing timely analysis on the 2009 H1N1 virus.展开更多
With the aid of stochastic delayed-feedback differential equations, we derive an analytic expression for the power spectra of reacting molecules included in a generic biological network motif that is incorporated with...With the aid of stochastic delayed-feedback differential equations, we derive an analytic expression for the power spectra of reacting molecules included in a generic biological network motif that is incorporated with a feedback mechanism and time delays in gene regulation. We systematically analyse the effects of time delays, the feedback mechanism, and biological stochasticity on the power spectra. It has been clarified that the time delays together with the feedback mechanism can induce stochastic oscillations at the molecular level and invalidate the noise addition rule for a modular description of the noise propagator. Delay-induced stochastic resonance can be expected, which is related to the stability loss of the reaction systems and Hopf bifurcation occurring for solutions of the corresponding deterministic reaction equations. Through the analysis of the power spectrum, a new approach is proposed to estimate the oscillation period.展开更多
Multiple repeats of membrane occupation and recognition nexus (MORN) motifs were detected in plant phosphatidylinositl monophosphate kinase (PIPK), a key enzyme in PI-signaling pathway. Structural analysis indicates t...Multiple repeats of membrane occupation and recognition nexus (MORN) motifs were detected in plant phosphatidylinositl monophosphate kinase (PIPK), a key enzyme in PI-signaling pathway. Structural analysis indicates that all the MORN motifs (with varied numbers at ranges of 7-9), which shared high homologies to those of animal ones, were located at N-terminus and sequentially arranged, except those of OsPIPK1 and AtPIPK7, in which the last MORN motif was separated others by an -100 amino-acid "island" region, revealing the presence of two kinds of MORN arrangements in plant PIPKs. Through employing a yeast-based SMET (sequence of membrane-targeting) system, the MORN motifs were shown being able to target the fusion proteins to cell plasma membrane, which were further confirmed by expression of fused MORN-GFP proteins. Further detailed analysis via deletion studies indicated the MORN motifs in OsPIPK 1, together with the 104 amino-acid "island" region are involved in the regulation of differential subcellular localization, i.e. plasma membrane or nucleus, of the fused proteins. Fat Western blot analysis of the recombinant MORN polypeptide, expressed in Escherichia coli, showed that MORN motifs could strongly bind to PA and relatively slightly to PI4P and PI(4,5)P2. These results provide informative hints on mechanisms of subcellular localization, as well as regulation of substrate binding, of plant PIPKs.展开更多
文摘Plasmodium (P.) falciparum is a pathogen that causes severe forms of malaria. Protein interactions have been shown to occur between P. falciparum and human erythrocytes in human blood. The Band 3 Anion Transporter (B3AT) protein is considered the main invasive pathway for the parasite in erythrocytes that causes clinical symptoms for malaria in humans. The interactions between P. falciparum parasites and erythrocytes along this receptor have previously been explored. Short linear motifs (SLIMs) are short linear mediator sequences that involve several biological processes, acting as mediators of protein interactions identifiable by computational tools such as SLiMFinder. For a given protein, the identification of SLIMs allows predicting its interactors. Using the SLIMs approach, protein-protein interaction network analyses between P. falciparum and its human host, were used to identify a tryptophan-rich protein, A5K5E5_PLAVS as an essential interactor of B3AT. To better understand the interaction mechanism, a guided protein-protein docking approach based on SLIM motifs was performed for human B3AT and A5K5E5_PLAVS. The highlights of this important interaction between P. falciparum and its human host have the potential to pave the way to identify new therapeutic candidates.
基金supported by the National Natural Science Foundation of China(Key Program),No.11932013the National Natural Science Foundation of China(General Program),No.82272255+2 种基金Armed Police Force High-Level Science and Technology Personnel ProjectThe Armed Police Force Focuses on Supporting Scientific and Technological Innovation TeamsKey Project of Tianjin Science and Technology Plan,No.20JCZDJC00570(all to XC)。
文摘Spinal cord injury involves non-reversible damage to the central nervous system that is characterized by limited regenerative capacity and secondary inflammatory damage.The expression of the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis exhibits significant differences before and after injury.Recent studies have revealed that the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis is closely associated with secondary inflammatory responses and the recruitment of immune cells following spinal cord injury,suggesting that this axis is a novel target and regulatory control point for treatment.This review comprehensively examines the therapeutic strategies targeting the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis,along with the regenerative and repair mechanisms linking the axis to spinal cord injury.Additionally,we summarize the upstream and downstream inflammatory signaling pathways associated with spinal cord injury and the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis.This review primarily elaborates on therapeutic strategies that target the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis and the latest progress of research on antagonistic drugs,along with the approaches used to exploit new therapeutic targets within the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis and the development of targeted drugs.Nevertheless,there are presently no clinical studies relating to spinal cord injury that are focusing on the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis.This review aims to provide new ideas and therapeutic strategies for the future treatment of spinal cord injury.
基金supported by National Natural Science Foundation of China(62101088,61801076,61971336)Natural Science Foundation of Liaoning Province(2022-MS-157,2023-MS-108)+1 种基金Key Laboratory of Big Data Intelligent Computing Funds for Chongqing University of Posts and Telecommunications(BDIC-2023-A-003)Fundamental Research Funds for the Central Universities(3132022230).
文摘Interconnection of all things challenges the traditional communication methods,and Semantic Communication and Computing(SCC)will become new solutions.It is a challenging task to accurately detect,extract,and represent semantic information in the research of SCC-based networks.In previous research,researchers usually use convolution to extract the feature information of a graph and perform the corresponding task of node classification.However,the content of semantic information is quite complex.Although graph convolutional neural networks provide an effective solution for node classification tasks,due to their limitations in representing multiple relational patterns and not recognizing and analyzing higher-order local structures,the extracted feature information is subject to varying degrees of loss.Therefore,this paper extends from a single-layer topology network to a multi-layer heterogeneous topology network.The Bidirectional Encoder Representations from Transformers(BERT)training word vector is introduced to extract the semantic features in the network,and the existing graph neural network is improved by combining the higher-order local feature module of the network model representation network.A multi-layer network embedding algorithm on SCC-based networks with motifs is proposed to complete the task of end-to-end node classification.We verify the effectiveness of the algorithm on a real multi-layer heterogeneous network.
文摘The image of Mulan is well known to the public as an important symbol in the dissemination of Chinese excellent traditional culture.This paper aims to summarise the mother-title from traditional canonical texts,to explore the content and value of sustainable IP development,and to study a large number of derivatives with the image of Mulan as the mother-title,based on the wide circulation of the prototype of the mother-title“The Poem of Mulan”(木兰辞)and the positive values conveyed by the content.Through the processing and imagination of scholars and writers on the mother text in the past generations,the image of Mulan has gradually formed a relatively stable cultural communication theme in the process of dissemination in China’s historical period,and many adaptations with international influence based on the mother title of Mulan have emerged in the foreign dissemination,so through the combing and summarisation of the textual works of various periods both at home and abroad,we will dig out the textual transmission of the mother title of Mulan,which is representative of the mother title of China’s excellent traditional culture,and the development of the Chinese spiritual core.The Development of the Chinese Spiritual Kernel.This paper adopts research methods such as documentary evidence method and discourse analysis to show the textual flow of Mulan’s parent theme in a more diversified form.
文摘This editorial summarizes the latest literature on the roles of neuronal PAS domain protein 2 and KN motif/ankyrin repeat domain 1 in type 2 diabetes(T2D).We highlight their involvement inβ-cell dysfunction,explore their potential as therapeutic targets,and discuss the implications for new treatment strategies.We offer valuable insights into relevant gene regulation and cellular mechanisms relevant for the targeted management of T2D.
文摘社区搜索的目标是从数据图中得到包含查询顶点的紧密子图,在社会学、生物学等领域有着广泛应用。针对现有基于子图连通性的社区模型的基础连通结构都是完全连通图,无法满足实际应用中用户对社区结构多样性的需求的问题,提出一种基于motif连通性的社区搜索方法,其中包括基于motif连通性的社区(MCC)模型以及两个相应的社区搜索算法——MPCS(Motif-Processed Community Search)算法和基于MP-index的社区搜索算法。MCC模型可以协助用户自由指定社区的基础连通结构,MPCS算法可以用来解决MCC的搜索问题。此外,提出两个分别针对motif实例搜索过程及所属社区判断过程的剪枝优化技术。最后,设计了MP-index以避免社区搜索过程中的冗余遍历操作。在多个真实数据集上进行实验的结果表明:剪枝优化可以使MPCS算法的耗时减少60%~85%,而基于MP-index的社区搜索算法相较于加入剪枝优化的MPCS算法,效率提升普遍达到了2~3个数量级。可见,所提方法在商品推荐和社交网络等问题上有着实际应用价值。
文摘软件动态胎记技术是实现混淆对抗的软件抄袭检测的有效手段之一.然而,多线程程序中线程交织的不确定性对其造成了不可忽视的影响;极端情况下,传统动态胎记技术甚至会判定同一个程序与其自身不存在抄袭关系.对此,提出从多线程程序在同一输入下的多条执行轨迹中进行相似部分的识别,并从中抽象出不易受线程交织影响的行为motifs来实现多线程程序的抄袭检测.该方法捕捉程序的动态执行轨迹,经过轨迹修剪、gram匹配以及扩展和抽象,从中提取motifs胎记建模多线程程序的行为;最终,通过衡量motifs胎记的相似性实现程序间潜在抄袭的判定.在一个包含234个不同版本多线程程序的公共数据集上开展的实验表明,motifs胎记是一种可靠的线程感知胎记方法,不仅可有效对抗当下主流的代码混淆技术,相比现有的2种多线程程序抄袭检测方法TreSB(thread-related system call birthmark)和TOB(thread-oblivious birthmark),也体现出更优秀的检测能力.
基金Science Foundation of Chongqing Municipal Education Commission (No. KJ060802)Natural Science Foundation Project of CQ CSTC (N0. 2007BB5228)Doctor Foundation of Chongqing Normal University (No. 956201)
文摘A cyclic bimetallic metal-organic complex [Zn(C)(H-fmpdc)(H2O)]2·2H2O (fmpdc = 4-(furan-2-yl)-2,6-dimethylpyridine-3,5-dicarboxylate) was synthesized and characterized by single-crystal X-ray analysis. The compound crystallizes in orthorhombic, space group Pbca with a = 12.905(2), b = 14.774(3), c = 16.833(3)A, V= 3029.4(10)A^3 Z = 4, Dc = 1.644 g/cm^3, F(000) = 1616, R = 0.0347 and wR = 0.0956 (I 〉 2σ(I)). There exist diverse supramolecular motifs (1-D, 2-D and 3-D) from distinct hydrogen bonds in the crystal structure of the title compound. The furanyl group has obvious contribution to the red-shift in the photoluminescent spectrum of the H2fmpdc ligand. The title compound 1 shows strong photoluminescence with emission maximum at 2 = 402 nm (λex.max = 367 nm).
文摘In this editorial preface, I briefly r eview cancer bioinformatics and introduce the four articles in this special issue highlighting important applications of the field: detection of chromatin states; detection of SNP- containing motifs and association with transcription factor-binding sites; improvements in functional enrichment modules; and gene association studies on aging and cancer. We expect this issue to provide bioinformatics scientists, cancer biologists, and clinical doctors with a better understanding of how cancer bioinformatics can be used to identify candidate biomarkers and targets and to conduct functional analysis.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10975015)the National Basic Research Program of China (Grant No. 2007CB814800)
文摘Recently, self-sustained oscillatory genetic regulatory networks (GRNs) have attracted significant attention in the biological field. Given a GRN, it is important to anticipate whether the network could generate oscillation with proper parameters, and what the key ingredients for the oscillation are. In this paper the ranges of some function-related parameters which are favorable to sustained oscillations are considered. In particular, some oscillatory motifs appearing with high-frequency in most of the oscillatory GRNs are observed. Moreover, there are some anti-oscillatory motifs which have a strong oscillation repressing effect. Some conclusions analyzing these motif effects and constructing oscillatory GRNs are provided.
文摘The 2009 H1N1 influenza pandemic has attracted worldwide attention. The new virus first emerged in Mexico in April, 2009 was identified as a unique combination of a triple- reassortant swine influenza A virus, composed of genetic information from pigs, hu- mans, birds, and a Eurasian swine influenza virus. Several recent studies on the 2009 H1N1 virus util-ized small datasets to conduct analysis. With new sequences available up to date, we were able to extend the previous research in three areas. The first was finding two networks of co-mutations that may po-tentially affect the current flu-drug binding sites on neuraminidase (NA), one of the two surface proteins of flu virus. The second was discovering a special stalk motif, which was dominant in the H5N1 strains in the past, in the 2009 H1N1 strains for the first time. Due to the high virulence of this motif, the second finding is significant in our current research on 2009 H1N1. The third was updating the phylogenetic an- alysis of current NA sequences of 2009 H1N1 and H5N1, which demonstrated that, in clear contrast to previous findings, the N1 sequences in 2009 are di-verse enough to cover different major branches of the phylogenetic tree of those in previous years. As the novel influenza A H1N1 virus continues to spread globally, our results highlighted the importance of performing timely analysis on the 2009 H1N1 virus.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10975019)the Foundation of the Ministry of Personnel of China for Returned Scholars (Grant No. MOP2006138)the Fundamental Research Funds for the Central Universities
文摘With the aid of stochastic delayed-feedback differential equations, we derive an analytic expression for the power spectra of reacting molecules included in a generic biological network motif that is incorporated with a feedback mechanism and time delays in gene regulation. We systematically analyse the effects of time delays, the feedback mechanism, and biological stochasticity on the power spectra. It has been clarified that the time delays together with the feedback mechanism can induce stochastic oscillations at the molecular level and invalidate the noise addition rule for a modular description of the noise propagator. Delay-induced stochastic resonance can be expected, which is related to the stability loss of the reaction systems and Hopf bifurcation occurring for solutions of the corresponding deterministic reaction equations. Through the analysis of the power spectrum, a new approach is proposed to estimate the oscillation period.
文摘Multiple repeats of membrane occupation and recognition nexus (MORN) motifs were detected in plant phosphatidylinositl monophosphate kinase (PIPK), a key enzyme in PI-signaling pathway. Structural analysis indicates that all the MORN motifs (with varied numbers at ranges of 7-9), which shared high homologies to those of animal ones, were located at N-terminus and sequentially arranged, except those of OsPIPK1 and AtPIPK7, in which the last MORN motif was separated others by an -100 amino-acid "island" region, revealing the presence of two kinds of MORN arrangements in plant PIPKs. Through employing a yeast-based SMET (sequence of membrane-targeting) system, the MORN motifs were shown being able to target the fusion proteins to cell plasma membrane, which were further confirmed by expression of fused MORN-GFP proteins. Further detailed analysis via deletion studies indicated the MORN motifs in OsPIPK 1, together with the 104 amino-acid "island" region are involved in the regulation of differential subcellular localization, i.e. plasma membrane or nucleus, of the fused proteins. Fat Western blot analysis of the recombinant MORN polypeptide, expressed in Escherichia coli, showed that MORN motifs could strongly bind to PA and relatively slightly to PI4P and PI(4,5)P2. These results provide informative hints on mechanisms of subcellular localization, as well as regulation of substrate binding, of plant PIPKs.