When and where proteins are made

Albert Einstein School of medicine at Yeshiva University and international partners have jointly developed a novel fluorescence microscopy technology, which for the first time shows when and where proteins are made When messenger RNA molecules (mRNAs) are translated into proteins in living cells, researchers can directly observe individual mRNAs The paper was published in the March 20 issue of science According to the report on March 20 (Beijing time) by the organization network of physicists, the technology is known as trick After experiments in living human cells and fruit flies, the researchers believe that the technology can help reveal the role of "illegal" protein synthesis in the development of abnormal and human diseases, including those related to Alzheimer's and memory disorders In the past, it was impossible to know exactly when and where mRNAs were translated into proteins Robert singer, CO director of the research and deputy director of the gerus lippa Center for biophotonics at Einstein Medical School, said: "this ability is crucial to the study of the molecular basis of diseases, for example, in the process of neurodegeneration, the disorder of protein synthesis in brain cells leads to memory loss." The instructions for making proteins are encoded in the nuclear genes, and the instructions will bring real proteins This involves two steps: the first step is called "transcription", where mRNAs "read" the DNA of the gene, and then these mRNAs come out of the nucleus and enter the cytoplasm to adhere to a ribosome structure Here, the second step is protein synthesis: take the mRNAs attached to the ribosome as a template to build a protein To visualize transcription, Singh and colleagues used a key event in the first round of transcription: ribosomes must replace an RNA binding protein on mRNAs to stick to them They synthesized mRNAs copies containing two fluorescent proteins (one red and one green) In the nucleus, there are red and green protein markers of mRNAs showing yellow color After entering the cytoplasm, the color will change according to the situation When mRNAs binds to ribosomes, ribose will replace the green fluorescent protein of mRNAs and make it appear red, so the mRNAs that successfully binds to ribosomes will appear red, and will be translated into protein; at the same time, the untranslated is yellow When experimenting with this technique, German researchers studied the expression of an mRNA called Oskar gene in the oocytes of Drosophila melanogaster They labeled Oskar's mRNAs with red and green fluorescent proteins and inserted them into the nucleus of the fly's oocyte "Using the trick technique, Oskar's mRNAs were not transcribed until they reached the posterior pole of the oocyte." "We used to have doubts about it, and now we have concrete evidence," Singh said Next, we will use this technique to analyze a series of regulatory events in the transcription of mRNAs "