氨基酸供给与内分泌互作调控乳蛋白合成的研究进展

限制性氨基酸研究是泌乳奶牛研究的热点之一,关于其影响乳蛋白合成途径而进行的一系列体内外研究表明:底物效应可能不是主要原因,更重要的是氨基酸及其构成作为信号因子对神经内分泌和细胞内信号通路的影响。本文从乳蛋白合成的影响因素入手,概括了氨基酸供给、激素分泌及二者相互作用对乳蛋白合成的调节,以期为阐明氨基酸供给影响乳蛋白合成的途径提供一定理论参考。

烟草花粉与雌蕊互作调控机制研究进展

授粉是植物生活史周期中的一个重要过程.茄科植物属于湿柱头,实心花柱.成功授粉起始于花粉粘附在成熟的柱头表面,接着水合、萌发,花粉管穿过柱头后沿着花柱传导组织细胞间隙朝着胚囊的方向生长,经过助细胞后释放精子完成双受精.在这个过程中,花粉外壁决定因子与花粉管生长通道中的各种成分相互作用,激活花粉管细胞内部的一系列生理生化反应.存在于烟草柱头、花柱传导组织细胞、子房和助细胞中的各种分泌物对于花粉细胞粘附、花粉管生长营养供给、信号传导、方向引导具有重要作用;另外,某些花粉决定因子与雌蕊成分的相互作用也可能导致自交不亲和与杂交不亲和.文章总结了烟草授粉后花粉与雌蕊相互作用涉及的物质及机理,这些物质主要包括蛋白质、多糖、脂类、激素、酶类和黄酮类等.

岭南师院刘锴栋课题组 揭示乙烯和生长素信号互作调控番木瓜果实采后成熟的机制

5月11日,The Plant Journal在线发表了岭南师范学院生命科学与技术学院刘锴栋课题组题为CpARF2 and CpEIL1 interact to mediate auxin-ethylene interaction and regulate fruit ripening in papaya的研究论文。该研究揭示了生长素响应因子CpARF2和乙烯信号途径转录因子CpEIL1互作调控番木瓜果实采后成熟的分子机理,为番木瓜果实采后成熟的调控提供了理论基础。番木瓜属于呼吸跃变型果实,果实采后在常温下迅速转黄、软化并完成后熟,贮藏期较短,限制了番木瓜产业的发展。

紫心甘薯IbMYB1上游7个调控蛋白的互作与表达分析

【目的】对前期筛选到的紫心甘薯IbMYB1上游7个调控蛋白(IbERF1、IbPDC、IbPGP19、IbSCF、IbWRKY1、IbJOX4和IbEIN3-2)的互作与表达进行分析,进一步阐明花色素苷在特定时空合成与积累的调控网络。【方法】采用酵母双杂交和双分子荧光互补试验,对7个调控因子之间的相互作用进行检测,使用荧光定量PCR对紫心甘薯和白心甘薯根不同发育时期花色素苷合成调控和筛选的上游调控因子进行基因表达特征分析。【结果】IbERF1与IbSCF、IbWRKY1存在相互作用。双分子荧光互补试验证实了酵母双杂交的试验结果。IbERF1基因在紫心甘薯根不同时期的表达量均低于白心甘薯,且随着根中花色素苷的积累其表达量逐渐降低,IbWRKY1和IbSCF基因在紫心甘薯和白心甘薯根不同发育时期中的表达量,与花色素苷的积累无明显的相关关系。【结论】IbMYB1上游调控蛋白IbERF1、IbSCF可分别与IbWRKY1形成复合物,以转录复合体的形式共同调控IbMYB1表达。推测IbERF1可能负调控花色素苷的合成,IbSCF和IbWRKY1参与紫心甘薯花色素苷的合成与调控,可能还存在更为复杂的机制。

南果梨PuLOX2S基因的鉴定及与 PuWRKY、PuMYB转录因子家族成员互作研究

以南果梨为试材,采用Tail-PCR、Y1H技术以及生物信息学方法,研究了PuLOX2S启动子结构与PuWRKY、PuMYB转录因子家族成员的互作关系,以期揭示PuLOX2S基因的调控元件。结果表明:PuLOX2S蛋白质与亚麻荠CsatLOX6、西洋白花菜ThjLOX6的亲缘关系较近,蛋白质二级结构中无规则卷曲占42.17%比例最高,该蛋白质在细胞质基质中发挥生物学作用;PuLOX2S基因启动子含ABRE、CAAT-box、TGACG-motif等多个转录因子结合位点;PuLOX2S-pro能够与PuWRKY2与PuMYB44发生显著互作,但与PuWRKY21互作不显著。该研究为深入解析南果梨香气合成分子机制提供了重要信息。

神经突触后膜蛋白Neuroligin-1的力-电感知及其耦合调控分子机制的研究

神经突触是神经元之间信号传递的重要结构基础,电信号及生物力学信号动态耦合调控神经突触的形成和成熟。神经突触的动态连接主要由突触黏附分子间特异性原位互作调控,但黏附分子是否通过感知力、电信号来动态调控突触形成及其分子机制至今并不清楚。该问题是生物力学、力生物学和神经生物学等研究领域的前沿难点。

上海交通大学林文慧团队综述拟南芥胚珠发生研究进展

2022年6月,上海交通大学林文慧团队在《Journal of Integrative Plant Biology》上在线发表了题为“Ovule initiation:the essential step controlling offspring number in Arabidopsis”的综述。论文系统总结了拟南芥胚珠发生的规律和机制,分别从胚珠发生前、胚珠发生时以及胚珠发生后3方面进行阐述,首先梳理了参与胎座形成和胚珠决定(胚珠发生的前提)的重要基因和信号;接着阐述了多胚珠原基群体起始的规律,并详细总结了植物激素及其信号互作调控胚珠发生的功能和机制;随后简要概述了胚珠发生后续的发育过程(胚珠发育、胚珠中雌配子体发育、受精过程、合子发育等)以及这些过程对植物后代数量的影响;最后提出了胚珠发生研究中尚未解决的问题,如胚珠发生的根本问题(原初信号)、胚珠发生的终止信号、是否存在第一个胚珠(the primary ovule,元珠猜想)等;并展望了未来研究热点(技术革新、环境影响、植物不同侧生器官发生的机制比较、动植物器官/形态特征均匀排列的机制比较等),以及该领域研究在提高多胚珠子房农作物产量中的应用前景,对相关领域的研究工作具有较高的参考价值。

Identification of an ｋB-like motif at the 5' upstream region of human lymphotoxin gene

Lymphotoxin(LT) is a glycoprotein secreted by activated T cell. The expression of LT gene is mainly regulated at the level of transcription. By using human LT DNA as a probe, we carried out a RNA dot blotting test and found that the longer the time of Jurkat human Tlymphoma cells exposed to the PMA and PHA, the more endogenous LT mRNA could be produced. Results of gel retardation assay showed that the nuclear extract from Jurkat cells treated with PMA and PHA formed different DNA-protein complexes. Changes in complex patterns were observed at various time intervals of PMA and PHA induction. A specific protein-binding site was mapped out to be a 22-bp sequence at the 5’upstream regioll of human LT gene by DNase I footprinting analysis. This region was similar to the sequence recognized by the proteins of NFｋB family The results of fragment competition and homology analysis indicated that the 22-bp sequence contains a ｋB-like motif only which is located at the base pairs -100 to -90 (5’-GGGGGCTTCCC-3’). Thus, the NF-ｋBlike factors were involved in the protein-DNA interaction.Furthermore, there were more than one retarded bands appearing in the gel retardation assay. It suggested that there may be several NF-ｋB-like factors involved in theregulation of LT gene transcription at the same site.

脱落酸调控种子萌发和休眠的研究进展

脱落酸(abscisic acid,ABA)是重要的植物激素之一。在促进种子休眠、抑制种子萌发的过程中,ABA发挥着举足轻重的调节作用。种子的萌发始于种子的吸水膨胀,止于胚轴的伸长,是高等植物生命周期中最为关键的阶段。在新生个体萌动的阶段,ABA与其他激素协同互作调控着这一重要的发育过程。现围绕ABA在种子休眠、萌发以及萌发后幼苗生长过程中的信号转导机制,着重从ABA与细胞分裂素和赤霉素等相互作用调控种子萌发的角度,概述相关的最新研究进展,并对今后的研究方向作出展望。

Identifying and annotating human bifunctional RNAs reveals their versatile functions

Bifunctional RNAs that possess both protein-coding and noncoding functional properties were less explored and poorly understood. Here we systematically explored the characteristics and functions of such human bifunctional RNAs by integrating tandem mass spectrometry and RNA-seq data. We first constructed a pipeline to identify and annotate bifunctional RNAs,leading to the characterization of 132 high-confidence bifunctional RNAs. Our analyses indicate that bifunctional RNAs may be involved in human embryonic development and can be functional in diverse tissues. Moreover, bifunctional RNAs could interact with multiple miRNAs and RNA-binding proteins to exert their corresponding roles. Bifunctional RNAs may also function as competing endogenous RNAs to regulate the expression of many genes by competing for common targeting miRNAs. Finally,somatic mutations of diverse carcinomas may generate harmful effect on corresponding bifunctional RNAs. Collectively,our study not only provides the pipeline for identifying and annotating bifunctional RNAs but also reveals their important gene-regulatory functions.

Influence of Air-Jet Vortex Generator Diameter on Separation Region

Control of shock wave and boundary layer interaction continues to attract a lot of attention. In recent decades several methods of interaction control have been investigated. The research has mostly concerned solid (vane type) vortex generators and transpiration methods of suction and blowing. This investigation concerns interaction control using air-jets to generate streamwise vortices. The effectiveness of air-jet vortex generators in controlling separation has been proved in a previous research. The present paper focuses on the influence of the vortex generator diameter on the separation region. It presents the results of experimental investigations and provides new guidelines for the design of air-jet vortex generators to obtain more effective separation control.

Building the DREAM interactome

DREAM/calsenilin/KChIP3 is a calcium binding protein of the neuronal calcium sensor superfamily.DREAM interacts with DRE(downstream regulatory element) sites in the DNA to regulate transcription and with many proteins to exert specialized functions in different subcellular compartments.Work from different laboratories has identified a growing list of interacting proteins that constitutes the DREAM interactome.The knowledge of these interactions has greatly contributed to the understanding of the various physiological functions of DREAM.

Interplay of transcription factors and microRNAs during embryonic hematopoiesis

Hematopoietic stem cells (HSCs), which are localized in the bone marrow of adult mammals, come from hematopoietic endothelium during embryonic stages. Although the basic processes of HSC generation and differentiation have been described in the past, the epigenetic regulation of embryonic hematopoiesis remains to be fully described. Here, by utilizing an in vitro differentiation system of mouse embryonic stem cells (ESCs), we identified more than 20 microRNAs that were highly enriched in embryonic hematopoietic cells, including some (e.g. miR-10b, miR-15b, and miR-27a) with previously unknown functions in blood formation. Luciferase and gene expression assays further revealed combinational binding and regulation of these microRNAs by key transcription factors in blood cells. Finally, bioinformatics and functional analyses supported an interactive regulatory control between transcription factors and microRNAs in hematopoiesis.

GMP-quadruplex-based hydrogels stabilized by lanthanide ions

This work describes the gelation behaviors and properties of a biological molecule, guanosine 5′-monophosphate disodium salt(GMP), in the presence of trivalent lanthanide ions. Hydrogels composed of GMP-quadruplexes were prepared by adjusting p H,through which the protonation of phosphate group was controlled to tune the interactions between lanthanide ions and GMP.Within the p H region of 2–6, the electrostatic interaction between lanthanide ions and phosphate group is hindered and the cation-dipole interaction acts as the main driving force for the formation of G-quadruplexes. All the hydrogels were found consisting of three-dimensional network of the intertwining one-dimensional nanofibers formed by the stacking G-quartets induced by lanthanide ions. A significant fluorescence enhancement of thioflavin T(Th T), a fluorescent molecule, was found to be triggered by the G-quadruplex structures, for which the rotation of chromophoric groups on Th T molecules were prohibited due to the implant into the G-quadruplex structures.