单分子磁镊旋转操控和基因转录调控动力学  

Rotation manipulation of single-molecule magnetic trapping and gene transcription regulation dynamics

作　　者：张志鹏 刘帅 张玉琼 熊影 韩伟静 陈同生 王爽 Zhang Zhi-Peng;Liu Shuai;Zhang Yu-Qiong;Xiong Ying;Han Wei-Jing;Chen Tong-Sheng;Wang Shuang(College of Biophotonics,South China Normal University,Guangzhou 510631,China;Songshan Lake Materials Laboratory,Dongguan 523808,China;Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China)

机构地区：[1]华南师范大学生物光子学研究院,广州510631 [2]松山湖材料实验室,东莞523808 [3]中国科学院物理研究所,北京100190

出　　处：《物理学报》2023年第21期1-8,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:12004420,32071228,12004271,12274308,62135003);中国科学院战略先导科技专项(B类)(批准号:XDB37000000);中国科学院青年创新促进会(批准号:2021009);广东省重点领域研发计划(批准号:21202107221900001,2022B0303040003);广东省基础与应用基础研究基金(批准号:2019A1515110186)资助的课题.

摘　　要：基因转录调控是生命体调节基因表达的重要过程,是保证遗传信息可控传递和维持基因组稳定性的关键步骤.单分子技术的发展为分子水平上探索基因转录调控动力学机制提供了新的研究范式,有力地推动了基因转录调控规律方面的研究进展.本文着重介绍了依据单分子磁镊旋转操控技术发展起来的操控超螺旋DNA的技术,借助超螺旋DNA的“放大”特点,实现了对DNA双螺旋动态打开过程的高通量、单碱基精度的测量;随后,介绍了单分子磁镊旋转操控技术在基因转录调控动力学研究中的应用情况,通过实时监测转录泡结构,实现对转录起始、延伸和终止等阶段的动力学表征,建立了一系列新的转录调控模型;最后,介绍了单分子磁镊旋转操控和单分子荧光成像技术联用方案,为研究复杂体系中的基因转录调控动力学机制提供了新的范式和范例.Gene transcription regulation is a key step for gene expression in all organisms and responsible for the transmission of genetic information and genome integrity.As one of the most important mechanisms in gene transcription,an RNA polymerase(RNAP)specifically interacts with and unwinds genome DNA to form a transcription bubble where a nascent RNA transcript is polymerized,taking one of the unwound DNA strands as its template.The RNAP translocates along the DNA to transcribe the whole gene by carrying the transcription bubble.In such a way,an RNAP completes its biological task of gene expression by physically acting as a molecular machinery.Thus,an RNAP molecule can be considered as a research object for physicists who are willing to uncover the mechanisms of life processes in a physical view.To achieve this,single-molecule method has been invented and used widely.As one of these methods,single-molecule magnetic trapping manipulates biological molecules by applying extension force or torque to the magnetic beads tethered through biological molecule to pre-coated glass surfaces by manipulating the position or rotation of a pair of magnets.A linear DNA molecule can be manipulated in such a way to generate plectonemes,i.e.DNA supercoils,under an extension force of 0.3 pN(1 pN=10−12 N),possessing the feature that the number of unwound base pairs of a supercoiled DNA can be observed by the changes in the number of supercoils reflected by the DNA extension changes.Thus,the DNA unwound by RNAP,i.e.the transcription bubble,during transcription can be observed in this way.By monitoring the kinetics of the transcription bubble in real time,this method thus allows singlemolecule detection with single-base resolution and a high-throughput data collection fashion in the kinetic studies of transcription.Owing to the advantages of the manipulation of DNA supercoils with single-molecule magnetic trapping,one can mimic the mechanistic feature of DNAs in vivo and characterize the kinetics of transcription under such conditions.Th

关 键 词：单分子磁镊旋转操控技术 超螺旋 DNA 基因转录调控 单分子动力学 

分 类 号：Q78[生物学—分子生物学]