{"id":84705,"date":"2021-01-20T08:15:30","date_gmt":"2021-01-20T06:15:30","guid":{"rendered":"https:\/\/www.technion.ac.il\/blog\/a-molecular-language\/"},"modified":"2021-01-20T08:15:30","modified_gmt":"2021-01-20T06:15:30","slug":"a-molecular-language","status":"publish","type":"post","link":"https:\/\/www.technion.ac.il\/en\/blog\/a-molecular-language\/","title":{"rendered":"A Molecular Language"},"content":{"rendered":"
Technion scientists are deciphering a mechanism that integrates all the stages of the mRNA lifecycle into a unified system<\/strong><\/p>\n Researchers from the Rappaport Faculty of Medicine at the Technion have uncovered a mechanism that coordinates the multi-stage process of gene expression: i.e., translating the information stored in the DNA into proteins. The study, published in Cell Reports, was led by molecular microbiology principal investigator Professor Mordechai Choder and Dr. Stephen Richard, with Dr. Tamar Ziv and Keren Bendalak of the Smoler Proteomics Center at the Technion.<\/p>\n The DNA can be thought of as the cell\u2019s \u201crecipe book,\u201d written using four \u201cletters\u201d \u2013 the nucleotide molecules. Every cell in our body contains DNA with the same nucleotide sequence (with some exceptions). However, the tissues of our body \u2013 muscle, bone, skin, etc. are quite different from each other in how they are formed and how they function.<\/p>\n How is possible that all tissues\u2019 cells contain the same DNA sequence but cells in different tissues express different sets of genes and function differently?<\/p>\n The answer lies in the regulation of gene expression \u2013 a wide range of mechanisms that, together, regulate which recipes out of the DNA-book will be \u201ccooked,\u201di.e., which genes would be expressed in each particular cell, in what amounts, and when. Although this recipe book is the same in all cells, the recipes cooked from it may be quite different.<\/p>\n The mechanisms that regulate gene expression may be broken into four major stages, revolving around the production, transfer, translation, and decay of messenger RNA (mRNA) molecules \u2013 each encodes a unique protein:<\/p>\n mRNA Synthesis and Maturation: the DNA is a large molecule (almost 2 meters long). In the process called \u201ctranscription\u201d, a gene encoding one protein (one recipe of the cookbook), is copied out into mRNA molecule, the nucleotide sequence of which is dictated by the DNA nucleotide sequence; this molecule carries the instructions for building the protein.<\/p>\n mRNA Transport from the cell nucleus into the cytoplasm, an intra-cell environment outside the nucleus, where proteins are produced. The nucleus can be thought of as a \u201csafe\u201d where the precious recipe book is kept. Recipes are copied out of it as necessary, but the book itself is never taken out of the safe.<\/p>\n mRNA Translation: this stage is carried out by the ribosome \u2013 the \u201cprotein factory.\u201d The ribosome reads the mRNA instruction (a single recipe) and produces a protein. Proteins are composed of amino acids, the sequence of which is dictated by the mRNA nucleotide sequence; the amino acids sequence determines the protein nature and functionality. \u00a0Proteins perform many functions in our body and are responsible, in part, for what we are.<\/p>\n mRNA Decay: like most molecules in our body, mRNAs are turned over. Their degradation is carried out by factors that, as Choder\u2019s group reported in 2013 (in Cell), also participate in transcription. Thus, mRNA synthesis and decay processes are linked.<\/p>\n \u201cEvery stage is regulated by a sophisticated mechanism, consists of many dozens of dedicated factors that execute the process and ensure its precision,\u201d said Professor Choder. \u201cI was interested in understanding the mechanism that integrates all these stages into a unified system, trying to obtain a bird\u2019s eye view. I have hypothesized that, for proper expression, all stages must be coordinated. It is for this reason that I have focused for the last 15 years on \u201czooming out\u201d our point of view from the discrete processes \u2013 transcription, translation, etc. to the whole system.\u201d<\/p>\n This continued research, performed on the baker\u2019s yeast S. cerevisiae, has yielded some dramatic discoveries, among them the discovery of mRNA coordinators, published in 2010 in Cell. The coordinators bind to the mRNA during transcription and accompany it throughout its life; a life that involves all the above-mentioned stages.<\/p>\n \u201cTo use a musical analogy, the coordinator is like a conductor of an orchestra, responsible for the coordination between the various instruments, that is to say \u2013 the different stages,\u201d continued Professor Choder. \u201cIt evolved because a \u2018false note\u2019 in the orchestra, i.e., discoordination among the stages, can have fateful consequences to the organism.\u201d<\/p>\n In the current article, the researchers went a step further and examined the means by which the stages\u2019 components and the coordinators communicate. They found that they use a \u201clanguage,\u201d the \u201cletters\u201d of which are small molecules (such as phosphoryl, methyl, and acetyl) and the \u201cwords\u201d are combinations thereof. These molecules bind to the coordinator, while it is attached to the mRNA, forming an mRNA\/coordinator\/small molecule complex. The coordinators, in turn, spread the \u201crumour\u201d among the stages.<\/p>\n The language contains many different words, each representing a certain combination of letters and the positions within the coordinator (which position within its amino acid sequence) that they bind. \u00a0Every \u201cword\u201d delivers information and commands to the various stages and affects their functionality. As for what kinds of information the stages need to deliver, they range from the simple (e.g., \u201call is well, you may proceed\u201d) to the more complicated (e.g., \u201cslow down, something\u2019s missing\u201d or \u201csend the mRNA to degradation \u2013 the problem is irreparable\u201d etc.). This mechanism allows the transfer of information between stages, thus reducing errors along the way. According to Prof. Choder, it would be interesting to see if other molecular systems use similar coordinators and a similar language (or a dialect).<\/p>\n The study was done with the generous support of the Israeli Science Foundation (ISF).<\/p>\n","protected":false},"excerpt":{"rendered":" Technion scientists are deciphering a mechanism that integrates all the stages of the mRNA lifecycle into a unified system Researchers from the Rappaport Faculty of Medicine at the Technion have uncovered a mechanism that coordinates the multi-stage process of gene expression: i.e., translating the information stored in the DNA into proteins. The study, published in… Continue Reading A Molecular Language<\/span><\/a><\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[24],"tags":[],"class_list":["post-84705","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"acf":[],"yoast_head":"\n<\/a>
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