Light serves as a crucial environmental cue which modulates plant growth and development, and which is controlled by multiple photoreceptors including the primary red light photoreceptor,phytochrome B(phyB). The signa...Light serves as a crucial environmental cue which modulates plant growth and development, and which is controlled by multiple photoreceptors including the primary red light photoreceptor,phytochrome B(phyB). The signaling mechanism of phyB involves direct interactions with a group of basic helix-loop-helix(bHLH) transcription factors, PHYTOCHROME-INTERACTING FACTORS(PIFs), and the negative regulators of photomorphogenesis, COP1 and SPAs. H2 A.Z is an evolutionarily conserved H2 A variant which plays essential roles in transcriptional regulation. The replacement of H2 A with H2 A.Z is catalyzed by the SWR1 complex. Here, we show that the Pfr form of phyB physically interacts with the SWR1 complex subunits SWC6 and ARP6. phyB and ARP6 coregulate numerous genes in the same direction,some of which are associated with auxin biosynthesis and response including YUC9, which encodes a rate-limiting enzyme in the tryptophandependent auxin biosynthesis pathway. Moreover,phyB and HY5/HYH act to inhibit hypocotyl elongation partially through repression of auxin biosynthesis. Based on our findings and previous studies, we propose that phyB promotes H2 A.Z deposition at YUC9 to inhibit its expression through direct phyB-SWC6/ARP6 interactions,leading to repression of auxin biosynthesis, and thus inhibition of hypocotyl elongation in red light.展开更多
Inplants,lightsignalstriggeraphotomorphogenic program involving transcriptome changes, epigenetic regulation, and inhibited hypocotyl elongation. The evolutionarily conserved histone variant H2 A.Z, which functions in...Inplants,lightsignalstriggeraphotomorphogenic program involving transcriptome changes, epigenetic regulation, and inhibited hypocotyl elongation. The evolutionarily conserved histone variant H2 A.Z, which functions in transcriptional regulation, is deposited in chromatin by the SWI2/SNF2-RELATED 1 complex(SWR1 c). However, the role of H2 A.Z in photomorphogenesis and its deposition mechanism remain unclear. Here, we show that in Arabidopsis thaliana, H2 A.Z deposition at its target loci is induced by light irradiation via NUCLEAR FACTOR-Y, subunit C(NF-YC) proteins, thereby inhibiting photomorphogenic growth. NF-YCs physically interact with ACTIN-RELATED PROTEIN6(ARP6), a key component of the SWR1 c that is essential for depositing H2 A.Z, in a lightdependent manner. NF-YCs and ARP6 function together as negative regulators of hypocotyl growth by depositing H2 A.Z at their target genes during photomorphogenesis. Our findings reveal an important role for the histone variant H2 A.Z in photomorphogenic growth and provide insights into a novel transcription regulatory node that mediates H2 A.Z deposition to control plant growth in response to changing light conditions.展开更多
AIM To detect the expression of Arpin, and determine its correlation with clinicopathological characteristics and the prognosis of gastric cancer (GC) patients. METHODS A total of 176 GC patients were enrolled as stud...AIM To detect the expression of Arpin, and determine its correlation with clinicopathological characteristics and the prognosis of gastric cancer (GC) patients. METHODS A total of 176 GC patients were enrolled as study subjects and classified into groups according to different clinicopathological variables. GC mucosal tissues were obtained via surgery. Another 43 paraffin-embedded tissue blocks of normal gastric epithelium (> 5 cm away from the edge of the tumor) were included in the control group. Immunohistochemistry (IHC) for the Arpin and Arp3 proteins was performed on the formalin-fixed, paraffin-embedded GC tissues. Additionally, expression of the Arpin protein in 43 normal gastric tissues was also determined using IHC. RESULTS Expression of the Arpin protein in GC was lower than that in normal gastric mucosa (30.68% vs 60.47%, P < 0.001). A chi(2) test of the 176 GC samples used for IHC showed that decreased Arpin expression was associated with advanced TNM stage (P < 0.01) and the presence or absence of lymph node metastasis (80.92% vs 35.56%, P < 0.001). Additionally, a significant correlation was observed between the expression of Arpin and the presence of the Arp2/3 complex in GC tissues (chi(2) = 30.535, P < 0.001). Moreover, a multivariate Cox regression analysis revealed that Arpin expression [hazard ratio (HR) = 0.551, P = 0.029] and TNM stage (HR = 5.344, P = 0.001) were independent prognostic markers for overall survival of GC patients. Regarding the 3-year disease-free survival (DFS), the recurrence rate of GC patients with low Arpin expression levels (median DFS 19 mo) was higher than that in the high-Arpin-expression group (median DFS 34 mo, P = 0.022). CONCLUSION Low Arpin levels are associated with clinicopathological variables and a poor prognosis in GC patients. Arpin may be regarded as a potential prognostic indicator in GC.展开更多
目的分析和预测亚洲带绦虫肌动相关蛋白2/3复合体亚单位4(Actin related protein2/3complexsubunit4,Arp2/3)基因及其编码蛋白的结构和特性。方法利用美国国家生物技术信息中心(NCBI,http://www.ncbi.nlm.nih.gov/)和瑞士生物信息学研...目的分析和预测亚洲带绦虫肌动相关蛋白2/3复合体亚单位4(Actin related protein2/3complexsubunit4,Arp2/3)基因及其编码蛋白的结构和特性。方法利用美国国家生物技术信息中心(NCBI,http://www.ncbi.nlm.nih.gov/)和瑞士生物信息学研究所的蛋白分析专家系统(ExPASY,http://ca.expasy.org/)中有关基因和蛋白的序列和结构信息分析的各种工具,结合其它生物信息学分析软件包,如Pcgene和Vector NTIsuite,从亚洲带绦虫全长cDNA质粒文库中识别Arp2/3基因及其编码区,分析、预测该基因编码蛋白质的理化特性、翻译后的修饰位点、功能域、亚细胞定位、拓扑结构、二级结构、三维空间构象等。结果该基因全长718bp,编码区为30-530,编码167个氨基酸,为全长基因。GenBank中与日本血吸虫Arp2/3氨基酸序列一致性达78%,相似性达90%。理论分子量为19533.9。没有跨膜区和各种亚细胞序列。预测3个主要的抗原表位为53～58,74～82,138～143均在Arp2/3空间结构的分子表面。结论应用生物信息方法从亚洲带绦虫成虫cDNA文库中筛选出Arp2/3基因。展开更多
Cell migration is essential to direct embryonic cells to specific sites at which their developmental fates are ultimately determined. However, the mechanism by which cell motility is regulated in embryonic development...Cell migration is essential to direct embryonic cells to specific sites at which their developmental fates are ultimately determined. However, the mechanism by which cell motility is regulated in embryonic development is largely unknown. Cortactin, a filamentous actin binding protein, is an activator of Arp2/3 complex in the nucleation of actin cytoskeleton at the cell leading edge and acts directly on the machinery of cell motility. To determine whether cortactin and Arp2/3 mediated actin assembly plays a role in the morphogenic cell movements during the early development of zebrafish, we initiated a study of cortactin expression in zebrafish embryos at gastrulating stages when massive cell migrations occur. Western blot analysis using a cortactin specific monoclonal antibody demonstrated that cortactin protein is abundantly present in em-bryos at the most early developmental stages. Immunostaining of whole-mounted embryo showed that cortactin immunoreactivity was associated with the embryonic shield, predominantly at the dorsal side of the embryos during gastrulation. In addition, cortactin was detected in the convergent cells of the epiblast and hypoblast, and later in the central nervous system. Im-munofluorescent staining with cortactin and Arp3 antibodies also revealed that cortactin and Arp2/3 complex colocalized at the periphery and many patches associated with the cell-to-cell junction in motile embryonic cells. Therefore, our data suggest that cortactin and Arp2/3 medi-ated actin polymerization is implicated in the cell movement during gastrulation and perhaps the development of the central neural system as well.展开更多
基金supported by The National Natural Science Foundation of China grants to Z.M.(31900609)The National Key Research and Development Program of China grant(2017YFA0503802)+1 种基金The National Natural Science Foundation of China grants to H.Q.Y.(31530085),W.W.(31900207)and T.G.(32000183)The Science and Technology Commission of Shanghai Municipality grant(18DZ2260500)。
文摘Light serves as a crucial environmental cue which modulates plant growth and development, and which is controlled by multiple photoreceptors including the primary red light photoreceptor,phytochrome B(phyB). The signaling mechanism of phyB involves direct interactions with a group of basic helix-loop-helix(bHLH) transcription factors, PHYTOCHROME-INTERACTING FACTORS(PIFs), and the negative regulators of photomorphogenesis, COP1 and SPAs. H2 A.Z is an evolutionarily conserved H2 A variant which plays essential roles in transcriptional regulation. The replacement of H2 A with H2 A.Z is catalyzed by the SWR1 complex. Here, we show that the Pfr form of phyB physically interacts with the SWR1 complex subunits SWC6 and ARP6. phyB and ARP6 coregulate numerous genes in the same direction,some of which are associated with auxin biosynthesis and response including YUC9, which encodes a rate-limiting enzyme in the tryptophandependent auxin biosynthesis pathway. Moreover,phyB and HY5/HYH act to inhibit hypocotyl elongation partially through repression of auxin biosynthesis. Based on our findings and previous studies, we propose that phyB promotes H2 A.Z deposition at YUC9 to inhibit its expression through direct phyB-SWC6/ARP6 interactions,leading to repression of auxin biosynthesis, and thus inhibition of hypocotyl elongation in red light.
基金supported by the National Natural Science Foundation of China(No.32000416)the Natural Science Foundation of Guangdong Province(No.2019A1515110885)。
文摘Inplants,lightsignalstriggeraphotomorphogenic program involving transcriptome changes, epigenetic regulation, and inhibited hypocotyl elongation. The evolutionarily conserved histone variant H2 A.Z, which functions in transcriptional regulation, is deposited in chromatin by the SWI2/SNF2-RELATED 1 complex(SWR1 c). However, the role of H2 A.Z in photomorphogenesis and its deposition mechanism remain unclear. Here, we show that in Arabidopsis thaliana, H2 A.Z deposition at its target loci is induced by light irradiation via NUCLEAR FACTOR-Y, subunit C(NF-YC) proteins, thereby inhibiting photomorphogenic growth. NF-YCs physically interact with ACTIN-RELATED PROTEIN6(ARP6), a key component of the SWR1 c that is essential for depositing H2 A.Z, in a lightdependent manner. NF-YCs and ARP6 function together as negative regulators of hypocotyl growth by depositing H2 A.Z at their target genes during photomorphogenesis. Our findings reveal an important role for the histone variant H2 A.Z in photomorphogenic growth and provide insights into a novel transcription regulatory node that mediates H2 A.Z deposition to control plant growth in response to changing light conditions.
文摘AIM To detect the expression of Arpin, and determine its correlation with clinicopathological characteristics and the prognosis of gastric cancer (GC) patients. METHODS A total of 176 GC patients were enrolled as study subjects and classified into groups according to different clinicopathological variables. GC mucosal tissues were obtained via surgery. Another 43 paraffin-embedded tissue blocks of normal gastric epithelium (> 5 cm away from the edge of the tumor) were included in the control group. Immunohistochemistry (IHC) for the Arpin and Arp3 proteins was performed on the formalin-fixed, paraffin-embedded GC tissues. Additionally, expression of the Arpin protein in 43 normal gastric tissues was also determined using IHC. RESULTS Expression of the Arpin protein in GC was lower than that in normal gastric mucosa (30.68% vs 60.47%, P < 0.001). A chi(2) test of the 176 GC samples used for IHC showed that decreased Arpin expression was associated with advanced TNM stage (P < 0.01) and the presence or absence of lymph node metastasis (80.92% vs 35.56%, P < 0.001). Additionally, a significant correlation was observed between the expression of Arpin and the presence of the Arp2/3 complex in GC tissues (chi(2) = 30.535, P < 0.001). Moreover, a multivariate Cox regression analysis revealed that Arpin expression [hazard ratio (HR) = 0.551, P = 0.029] and TNM stage (HR = 5.344, P = 0.001) were independent prognostic markers for overall survival of GC patients. Regarding the 3-year disease-free survival (DFS), the recurrence rate of GC patients with low Arpin expression levels (median DFS 19 mo) was higher than that in the high-Arpin-expression group (median DFS 34 mo, P = 0.022). CONCLUSION Low Arpin levels are associated with clinicopathological variables and a poor prognosis in GC patients. Arpin may be regarded as a potential prognostic indicator in GC.
文摘目的分析和预测亚洲带绦虫肌动相关蛋白2/3复合体亚单位4(Actin related protein2/3complexsubunit4,Arp2/3)基因及其编码蛋白的结构和特性。方法利用美国国家生物技术信息中心(NCBI,http://www.ncbi.nlm.nih.gov/)和瑞士生物信息学研究所的蛋白分析专家系统(ExPASY,http://ca.expasy.org/)中有关基因和蛋白的序列和结构信息分析的各种工具,结合其它生物信息学分析软件包,如Pcgene和Vector NTIsuite,从亚洲带绦虫全长cDNA质粒文库中识别Arp2/3基因及其编码区,分析、预测该基因编码蛋白质的理化特性、翻译后的修饰位点、功能域、亚细胞定位、拓扑结构、二级结构、三维空间构象等。结果该基因全长718bp,编码区为30-530,编码167个氨基酸,为全长基因。GenBank中与日本血吸虫Arp2/3氨基酸序列一致性达78%,相似性达90%。理论分子量为19533.9。没有跨膜区和各种亚细胞序列。预测3个主要的抗原表位为53～58,74～82,138～143均在Arp2/3空间结构的分子表面。结论应用生物信息方法从亚洲带绦虫成虫cDNA文库中筛选出Arp2/3基因。
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.30270692&30271034).
文摘Cell migration is essential to direct embryonic cells to specific sites at which their developmental fates are ultimately determined. However, the mechanism by which cell motility is regulated in embryonic development is largely unknown. Cortactin, a filamentous actin binding protein, is an activator of Arp2/3 complex in the nucleation of actin cytoskeleton at the cell leading edge and acts directly on the machinery of cell motility. To determine whether cortactin and Arp2/3 mediated actin assembly plays a role in the morphogenic cell movements during the early development of zebrafish, we initiated a study of cortactin expression in zebrafish embryos at gastrulating stages when massive cell migrations occur. Western blot analysis using a cortactin specific monoclonal antibody demonstrated that cortactin protein is abundantly present in em-bryos at the most early developmental stages. Immunostaining of whole-mounted embryo showed that cortactin immunoreactivity was associated with the embryonic shield, predominantly at the dorsal side of the embryos during gastrulation. In addition, cortactin was detected in the convergent cells of the epiblast and hypoblast, and later in the central nervous system. Im-munofluorescent staining with cortactin and Arp3 antibodies also revealed that cortactin and Arp2/3 complex colocalized at the periphery and many patches associated with the cell-to-cell junction in motile embryonic cells. Therefore, our data suggest that cortactin and Arp2/3 medi-ated actin polymerization is implicated in the cell movement during gastrulation and perhaps the development of the central neural system as well.
