用AFM观察小白鼠心肌核DNA片段的基因体外表达和垃圾DNA的相互作用

Observation of Interaction between Gene in vitro Expression of Mouse Cardiac Nuclei and Junk DNA by Atomic Force Microscopy

用AFM直接现场观察、体外表达等实验技术组合,观察到小白鼠(Balb/c)心肌核DNA片段的基因在体外表达过程中形成的nmRNA(n=9)[1]线型链状复合体,处于垃圾DNA片段的特定的“翻译平台”上,其每种mRNA两端非共价键分别结合自己编码蛋白质(即分子开关),中间的编码序列均非共价结合完全可解离的翻译活性因子等多种蛋白质[1～2]:这些蛋白质可能均由垃圾DNA片段的极复杂的立体结构所形成的、匹配协同的、专一性蛋白质通路所调控,该通路对蛋白质按顺序分别进行特异性双向调控。核内nmRNA线型链状复合体在体外可翻译出LDH等蛋白质,并显示nmRNA翻译的“群体效应”。用AFM还观察到胞质制取的nmRNA(n=12)线型链状复合体(无垃圾DNA存在),体外翻译出少量LDH等蛋白质,并显示nmRNA翻译的“群体效应”。本工作展示了未来运用AFM观察体外表达等生物学反应,研究基因表达与调控机制及其与垃圾DNA相互作用的前景。

Combining direct observation and in vitro expression experiments on expressive products of mouse （Balb/C） cardiac muscle genome by atomic force microscopy（AFM）, n mRNA（n=9） linear chain complexes are located on specific platform associated with junk DNA observed by AFM, two ends of each kind of mRNA noncovalently bind proteins they encode respectively（molecular switch）, middle encoding sequences noncovalently bind soluble active protein factors; These proteins may be dually regulated by specific, matched protein pathways of structurally complex junk DNA. Nucleus n mRNA linear chain complexes can in vitro translate proteins, such as LDH, and show “population effect” of n mRNA translation, Cytoplasmic n mRNA （n=12） linear chain complex （no junk DNA） were also observed by AFM and in vitro translate some LDH proteins, showing population effect of n mRNA translation. This work highlights prospects that AFM can be used for observing biological reaction, such as in vitro expression, studying gene expression, regulation and function of junk DNA.