The latest chapter of protein modification

The important protein of protein modification is the basic functional unit of cell function, whose expression is regulated by genome and epigenetics Generally, proteins need to be modified in different degrees after expression to perform the required functions This post-translational modification process is strictly regulated by a series of modified and unmodified enzymes, which makes proteins show a certain stable or dynamic specific function in a certain instant Protein post-translational modification (PTM) increases the functional diversity of proteome by covalently adding functional groups or proteins, regulating the proteolysis of subunits or the degradation of the whole protein These modifications include phosphorylation, glycosylation, nitrosylation, methylation, acetylation, lipopolysis and proteolysis, and affect almost all aspects of normal cell biology and pathogenesis Protein phosphorylation, the most common PTM, has been detected in about 17500 human gene products Post-translational modification is the key mechanism to increase proteomic diversity Although the genome contains only 20000 to 25000 genes, it is estimated that the proteome contains more than 1 million proteins Changes in transcription and mRNA levels increase the size of the transcriptome relative to the genome, and numerous different post-translational modification indices increase the complexity of the proteome relative to the transcriptome and genome Therefore, the recognition and understanding of PTM is very important for cell biology and disease treatment and prevention (3D schematic diagram of protein modification) the research progress of protein modification is based on the heterogeneity and low relative abundance of post-translational modified proteins The research of post-translational modified proteins mainly uses the existing proteomic technology systems including electrophoresis, chromatography, mass spectrometry and bioinformatics Tools, to enrich and separate the modified protein or peptide segment, eliminate the heterogeneity caused by modification and mark the modified site, so that it has a difference with the theoretical quality This difference is detected by mass spectrometry, so as to identify the protein, and identify the modified site by tandem mass spectrometry PTMs exist widely in eukaryotes, which is very important for signal transduction and life activities However, the identification of PTMs is more difficult than that of unmodified peptides Protein phosphorylation is one of the most popular and deeply studied modification methods in vivo Among them, tyrosine phosphorylation, especially the phosphorylation of tyrosine kinase receptor, has been proved to play a key role in the induction and growth of cancer cells A variety of small molecular inhibitors and monoclonal antibodies targeting different tyrosine kinase receptors have also been developed as one of the treatments for cancer Linear drugs At present, many post-translational modifications have been studied, including phosphorylation, acetylation, methylation and ubiquitination (basic modification type) phosphorylation research methods and key technologies are: immunoprecipitation, flow cytometry, two-dimensional gel electrophoresis, solid-phase metal affinity chromatography The main research methods for acetylation include: identification of acetylation sites by bio mass spectrometry, identification of acetylation sites by acetylation antibodies based on specific identification of acetyl lysine residues, identification of acetylation sites based on labeled substrates, etc The main research methods for methylation are: methylation specific PCR, bisulfite sequencing, high-resolution melting curve The research methods and key technologies of glycosylation include: radioactive labeling, molecular fluorescence labeling, electrophoresis, agglutinin labeling, antibody labeling, chemical enzyme labeling, etc At present, the technology types of ubiquitin protein exploration are relatively monotonous In the detection of ubiquitin, the location of ubiquitin target and the exploration of the properties of ubiquitin itself, these technologies must be improved and perfected constantly For example, the traditional study of post-translational modification of proteins mainly depends on the immunoassay technology or radioactive labeling technology based on specific antibodies These methods play an irreplaceable role in the study of cell signal transduction mediated by single site post-translational modification However, due to the shortcomings of the above techniques, such as high operational requirements and long preparation cycle of specific antibodies, it is difficult to achieve large-scale detection of protein post translation modifications In recent years, with the rapid development of proteomic strategy based on LC-MS, protein modification detection technology provides a powerful research tool for protein post-translational modification at the system level Moreover, proteomics based on mass spectrometry has greatly expanded people's understanding of the occurrence and dynamics of protein post-translational modification (PTM) Up to now, quantitative proteomics is mainly used to study the regulation of PTM in cell culture model, and provide new insights for the role of abnormal PTM in human diseases Mass spectrometry library has been widely used in the quantitative analysis of various proteins, especially in the application of quantitative known proteins (instruments and equipment) at present, the new technology strategy of immunoaffinity enrichment of PTM peptide with monoclonal antibody and LC-MS / MS analysis has attracted attention in many post-translational modifications The basic operation method of ptmscan technology includes using 9m urea lysate to extract 10 Mg protein) was cleaved to obtain protein lysate, which was digested by endonuclease (usually trypsin) to obtain protein peptide mixture The peptide mixture was purified by C18 purification column, and then the peptide with different protein post-translational modified motif antibody was enriched and purified by affinity chromatography-tandem mass spectrometry (L C-ms / MS) In addition, the analytical methods of bioinformatics have also made progress in the field of PTM research In recent years, with the development of proteomics technology, bioinformatics research based on proteomics, especially modified proteomics data, can provide a whole and deeper understanding of post-translational modification In 1999, nikolaj Blom of the center for biological sequence analysis (CBS) in Denmark used 210 known tyrosine, 584 serine and 108 threonine phosphorylation sites confirmed by experiments as training sets, and used neural network algorithm to realize non-specific training for the first time (non specific) protein phosphorylation site prediction Since then, similar experiments have been carried out gradually, and research has come out gradually In a foreign work comparing normal skin and skin cancer tissue of mice, combined with quantitative proteome and quantitative phosphorylation group data, 47.3% of the proteins were regulated in protein and phosphorylation level, while more than half of the proteins were only regulated in phosphorylation level It can be predicted that the cooperation between computation and experiment, and the verification of prediction results by experimental methods or at least partial verification, has become a research trend in the field (bioinformatics decoding protein modification) Biovalley will hold 2018 protein modification and disease seminar in Shanghai from October 26 to 27, 2018 This conference will invite domestic experts in this field to present the latest progress in basic research, regulatory methods, detection methods and analytical technologies of protein modification from different perspectives and levels, focusing on the types and mechanisms of protein modification, the relationship with disease and drug research and development, so as to provide a cutting-edge communication platform for participants and promote basic research To practical application Welcome to the conference Official website of the conference: http://meeting.bioon.com/2018promd 1 Liu Ting, Ma Chengjie, Yuan Bifeng, et al Modification histology: analytical modification of biomolecular function [J] Chinese Science: Chemistry, 2018 (5) 2 Li Zhenya, Gu Hongbo New technical strategies for post translation modification proteomics research [J] Chemistry of life, 2014, 34 (2): 000214-220 3 Tang Jia Research on new methods of high efficiency enrichment and identification of phosphorylated and glycosylated proteins based on functional materials [D] Fudan University, 2010.4 Lin Lin Lin, Luo Shusheng, Wang lingjue, et al Progress and application of chromatography-mass spectrometry in post-translational modification of proteins [J] Analytical chemistry, 2015, 43 (10): 1479-1489.5 Lundell l s, savikj m, kostovski e, et al Protein translation， proteolysis and autophagy in human skeletal muscle atrophy after spinal cord injury[J] Acta Physiologica， 2018， 223(3):e13051 6. Huang G， Li J Feature Extractions for Computationally Predicting Protein Post-translational Modifications[J] Current Bioinformatics， 2018， 12 7. Johnson E S Protein modification by SUMO.[J] Annual Review of Biochemistry， 2004， 26(5):332-333