TCP family as plant specific transcription factor, plays an important role in different aspects of plant development. In order to screen TCP family members in tobacco, the homologous sequences of tobacco and Arabidopsis TCP family were identified by genome-wide homologous alignment. The physicochemical properties, phylogenetic relationships and cis-acting elements were analyzed by bioinformatics. The homologous genes of AtTCP3/AtTCP4 were screened, and RT-qPCR was used to detect the changes of gene expression upon 20% PEG6000 treatment. The results show that tobacco contains 63 TCP family members. Their amino acid sequence length ranged from 89 aa to 596 aa, and their protein hydropathicity grand average of hydropathicity (GRAVY) ranged from -1.147 to 0.125. The isoelectric point (pI) ranges from 4.42 to 9.94, the number of introns is 0 to 3, and the subcellular location is all located in the nucleus. The results of conserved domain and phylogenetic relationship analysis showed that the tobacco TCP family can be divided into PCF, CIN and CYC/TB1 subfamilies, and each subfamily has a stable sequence. The results of cis-acting elements in gene promoter region showed that TCP family genes contain low docile acting elements (LTR) and a variety of stress and metabolic regulation related elements (MYB, MYC). Analysis of gene expression patterns showed that AtTCP3/AtTCP4 homologous genes (NtTCP6, NtTCP28, NtTCP30, NtTCP33, NtTCP42, NtTCP57, NtTCP63) accounted for 20% PEG6000 treatment significantly up-regulated/down-regulated expression, and NtTCP30 and NtTCP57 genes were selected as candidate genes in response to drought. The results of this study analyzed the TCP family in the tobacco genome and provided candidate genes for the study of drought-resistance gene function and variety breeding in tobacco.
Nicotiana/genetics* ; Phylogeny ; Plant Breeding ; Amino Acid Sequence ; Arabidopsis ; Polyethylene Glycols

Tumor is a serious threat to human health. At present, surgical resection, chemoradiotherapy, targeted therapy and immunotherapy are the main therapeutic strategies. Monoclonal antibody has gradually become an indispensable drug type in the clinical treatment of cancer due to its high efficiency and low toxicity. Phage antibody library technology (PALT) is a novel monoclonal antibody preparation technique. The recombinant immunoglobulin variable region of heavy chain (VH)/variable region of light chain (VL) gene is integrated into the phage vector, and the antibody is expressed on the phage surface in the form of fusion protein to obtain a diverse antibody library. Through the process of adsorption-elution-amplification, the antibody library can be screened to obtain the antibody molecule with specific binding antigen as well as its gene sequence. PALT has the advantages of short antibody production cycle, strong plasticity of antibody structure, large antibody yield, high diversity and direct production of humanized antibodies. It has been used in screening tumor markers and preparation of antibody drugs for breast cancer, gastric cancer, lung cancer and liver cancer. This article reviews the recent progress and the application of PALT in tumor therapy.
Humans ; Bacteriophages/genetics* ; Immunoglobulin Variable Region/genetics* ; Gene Library ; Antibodies, Monoclonal/therapeutic use* ; Immunotherapy ; Peptide Library

Single chain antibody fragment (scFv) is a small molecule composed of a variable region of heavy chain (VH) and a variable region of light chain (VL) of an antibody, and these two chains are connected by a flexible short peptide. scFv is the smallest functional fragment with complete antigen-binding activity, which contains both the antibody-recognizing site and the antigen-binding site. Compared with other antibodies, scFv has the advantages of small molecular weight, strong penetration, low immunogenicity, and easy expression. Currently, the most commonly used display systems for scFv mainly include the phage display system, ribosome display system, mRNA display system, yeast cell surface display system and mammalian cell display system. In recent years, with the development of scFv in the field of medicine, biology, and food safety, they have also attracted much attention in the sectors of biosynthesis and applied research. This review summarizes the advances of scFv display systems in recent years in order to facilitate scFv screening and application.
Animals ; Immunoglobulin Variable Region/genetics* ; Immunoglobulin Fragments/metabolism* ; Single-Chain Antibodies/metabolism* ; Peptide Library ; Mammals/genetics*

Yeast surface display (YSD) is a technology that fuses the exogenous target protein gene sequence with a specific vector gene sequence, followed by introduction into yeast cells. Subsequently, the target protein is expressed and localized on the yeast cell surface by using the intracellular protein transport mechanism of yeast cells, whereas the most widely used YSD system is the α-agglutinin expression system. Yeast cells possess the eukaryotic post-translational modification mechanism, which helps the target protein fold correctly. This mechanism could be used to display various eukaryotic proteins, including antibodies, receptors, enzymes, and antigenic peptides. YSD has become a powerful protein engineering tool in biotechnology and biomedicine, and has been used to improve a broad range of protein properties including affinity, specificity, enzymatic function, and stability. This review summarized recent advances in the application of YSD technology from the aspects of library construction and screening, antibody engineering, protein engineering, enzyme engineering and vaccine development.
Saccharomyces cerevisiae/metabolism* ; Protein Engineering ; Biotechnology ; Antibodies/metabolism* ; Amino Acid Sequence

Sepsis is a life-threatening organ dysfunction caused by dysregulated body response to infection. It is also one of the major causes of death in critically ill patients. Over the past few years, despite the continuous improvement in the treatment of sepsis, there is no specific treatment, clinical morbidity and mortality are still rising. Therefore, finding effective methods to treat sepsis and reduce mortality is an urgent clinical problem. Histone modification is an epigenetic modification that produces heritable phenotypic changes without altering the DNA sequence. In recent years, many studies have shown that histone modification is closely related to sepsis. This review discusses the mechanism of histone modification in the pathogenesis of sepsis from the aspects of inflammatory factors, signaling pathways, and macrophage polarization, in aimed to provide reference for the clinical treatment of sepsis.
Humans ; Histone Code ; Sepsis/metabolism* ; Critical Illness ; Macrophage Activation

The purpose of this study was to clone and characterize the ZFP36L1 (zinc finger protein 36-like 1) gene, clarify its expression characteristics, and elucidate its expression patterns in different tissues of goats. Samples of 15 tissues from Jianzhou big-eared goats, including heart, liver, spleen, lung and kidney were collected. Goat ZFP36L1 gene was amplified by reverse transcription-polymerase chain reaction (RT-PCR), then the gene and protein sequence were analyzed by online tools. Quantitative real-time polymerase chain reaction (qPCR) was used to detect the expression level of ZFP36L1 in intramuscular preadipocytes in different tissues and adipocytes of goat at different differentiation stages. The results showed that the length of ZFR36L1 gene was 1 224 bp, and the coding sequence (CDS) region was 1 017 bp, encoding 338 amino acids, which was a non-secretory unstable protein mainly located in nucleus and cytoplasm. Tissue expression profile showed that ZFP36L1 gene was expressed in all selected tissues. In visceral tissues, the small intestine showed the highest expression level (P < 0.01). In muscle tissue, the highest expression level was presented in longissimus dorsi muscle (P < 0.01), whereas the expression level in subcutaneous adipose tissue was significantly higher than that in other tissues (P < 0.01). The results of induced differentiation showed that the expression of this gene was up-regulated during adipogenic differentiation of intramuscular precursor adipocytes (P < 0.01). These data may help to clarify the biological function of the ZFP36L1 gene in goat.
Animals ; Goats/genetics* ; Amino Acid Sequence ; Liver ; Cloning, Molecular

Heat shock proteins (HSPs) widely exist in all organisms, the structures of which are usually extraordinarily conservative. They are also well-known stress proteins that are involved in response to physical, chemical and biological stresses. HSP70 is an important member of the HSPs family. In order to study the roles of amphibians HSP70 during infection, the cDNA sequence of Rana amurensis hsp70 family genes were cloned by homologous cloning method. The sequence characteristics, three-dimensional structure and genetic relationship of Ra-hsp70s were analyzed by bioinformatics methods. The expression profiles under bacterial infection were also analyzed by real-time quantitative PCR (qRT-PCR). Expression and localization of HSP70 protein were tested by immunohistochemical techniques. The results showed that three conservative tag sequences of HSP70 family, HSPA5, HSPA8 and HSPA13, were found in HSP70. Phylogenetic tree analysis indicated four members are distributed in four different branches, and members with the same subcellular localization motif are distributed in the same branch. The relative expression levels of the mRNA of four members were all significantly upregulated (P < 0.01) upon infection, but the time for up-regulating the expression levels were diverse in different tissues. The immunohistochemical analysis showed that HSP70 was expressed to different degrees in the cytoplasm of liver, kidney, skin and stomach tissue. The four members of Ra-hsp70 family have ability to respond bacterial infection to varying degrees. Therefore, it was proposed that they are involved in biological processes against pathogen and play different biological functions. The study provides a theoretical basis for functional studies of HSP70 gene in amphibians.
Heat-Shock Proteins/genetics* ; Phylogeny ; Amino Acid Sequence ; HSP70 Heat-Shock Proteins/metabolism* ; Stress, Physiological

Antimicrobial peptides (AMPs) are small molecule peptides that are widely found in living organisms with broad-spectrum antibacterial activity and immunomodulatory effect. Due to slower emergence of resistance, excellent clinical potential and wide range of application, AMP is a strong alternative to conventional antibiotics. AMP recognition is a significant direction in the field of AMP research. The high cost, low efficiency and long period shortcomings of the wet experiment methods prevent it from meeting the need for the large-scale AMP recognition. Therefore, computer-aided identification methods are important supplements to AMP recognition approaches, and one of the key issues is how to improve the accuracy. Protein sequences could be approximated as a language composed of amino acids. Consequently, rich features may be extracted using natural language processing (NLP) techniques. In this paper, we combine the pre-trained model BERT and the fine-tuned structure Text-CNN in the field of NLP to model protein languages, develop an open-source available antimicrobial peptide recognition tool and conduct a comparison with other five published tools. The experimental results show that the optimization of the two-phase training approach brings an overall improvement in accuracy, sensitivity, specificity, and Matthew correlation coefficient, offering a novel approach for further research on AMP recognition.
Anti-Bacterial Agents/chemistry* ; Amino Acid Sequence ; Antimicrobial Cationic Peptides/chemistry* ; Antimicrobial Peptides ; Natural Language Processing

Nitrate is the main form of inorganic nitrogen that crop absorbs, and nitrate transporter 2 (NRT2) is a high affinity transporter using nitrate as a specific substrate. When the available nitrate is limited, the high affinity transport systems are activated and play an important role in the process of nitrate absorption and transport. Most NRT2 cannot transport nitrates alone and require the assistance of a helper protein belonging to nitrate assimilation related family (NAR2) to complete the absorption or transport of nitrates. Crop nitrogen utilization efficiency is affected by environmental conditions, and there are differences between varieties, so it is of great significance to develop varieties with high nitrogen utilization efficiency. Sorghum bicolor has high stress tolerance and is more efficient in soil nitrogen uptake and utilization. The S. bicolor genome database was scanned to systematically analyze the gene structure, chromosomal localization, physicochemical properties, secondary structure and transmembrane domain, signal peptide and subcellular localization, promoter region cis-acting elements, phylogenetic evolution, single nucleotide polymorphism (SNP) recognition and annotation, and selection pressure of the gene family members. Through bioinformatics analysis, 5 NRT2 gene members (designated as SbNRT2-1a, SbNRT2-1b, SbNRT2-2, SbNRT2-3, and SbNRT2-4) and 2 NAR2 gene members (designated as SbNRT3-1 and SbNRT3-2) were identified, the number of which was less than that of foxtail millet. SbNRT2/3 were distributed on 3 chromosomes, and could be divided into four subfamilies. The genetic structure of the same subfamilies was highly similar. The average value of SbNRT2/3 hydrophilicity was positive, indicating that they were all hydrophobic proteins, whereas α-helix and random coil accounted for more than 70% of the total secondary structure. Subcellular localization occurred on plasma membrane, where SbNRT2 proteins did not contain signal peptides, but SbNRT3 proteins contained signal peptides. Further analysis revealed that the number of transmembrane domains of the SbNRT2s family members was greater than 10, while that of the SbNRT3s were 2. There was a close collinearity between NRT2/3s of S. bicolor and Zea mays. Protein domains analysis showed the presence of MFS_1 and NAR2 protein domains, which supported executing high affinity nitrate transport. Phylogenetic tree analysis showed that SbNRT2/3 were more closely related to those of Z. mays and Setaria italic. Analysis of gene promoter cis-acting elements indicated that the promoter region of SbNRT2/3 had several plant hormones and stress response elements, which might respond to growth and environmental cues. Gene expression heat map showed that SbNRT2-3 and SbNRT3-1 were induced by nitrate in the root and stem, respectively, and SbNRT2-4 and SbNRT2-3 were induced by low nitrogen in the root and stem. Non-synonymous SNP variants were found in SbNRT2-4 and SbNRT2-1a. Selection pressure analysis showed that the SbNRT2/3 were subject to purification and selection during evolution. The expression of SbNRT2/3 gene and the effect of aphid infection were consistent with the expression analysis results of genes in different tissues, and SbNRT2-1b and SbNRT3-1 were significantly expressed in the roots of aphid lines 5-27sug, and the expression levels of SbNRT2-3, SbNRT2-4 and SbNRT3-2 were significantly reduced in sorghum aphid infested leaves. Overall, genome-wide identification, expression and DNA variation analysis of NRT2/3 gene family of Sorghum bicolor provided a basis for elucidating the high efficiency of sorghum in nitrogen utilization.
Nitrate Transporters ; Nitrates/metabolism* ; Sorghum/metabolism* ; Anion Transport Proteins/metabolism* ; Phylogeny ; Protein Sorting Signals/genetics* ; Nitrogen/metabolism* ; DNA ; Gene Expression Regulation, Plant ; Plant Proteins/metabolism*

Polygonum cuspidatum polyketide synthase 1 (PcPKS1) has the catalytic activity of chalcone synthase (CHS) and benzylidene acetone synthase (BAS), which can catalyze the production of polyketides naringenin chalcone and benzylidene acetone, and then catalyze the synthesis of flavonoids or benzylidene acetone. In this study, three amino acid sites (Thr133, Ser134, Ser33) that may affect the function of PcPKS1 were identified by analyzing the sequences of PcPKS1, the BAS from Rheum palmatum and the CHS from Arabidopsis thaliana, as well as the conformation of the catalytic site of the enzyme. Molecular modification of PcPKS1 was carried out by site-directed mutagenesis, and two mutants were successfully obtained. The in vitro enzymatic reactions were carried out, and the differences in activity were detected by high performance liquid chromatography (HPLC). Finally, mutants T133LS134A and S339V with bifunctional activity were obtained. In addition to bifunctional activities of BAS and CHS, the modified PcPKS1 had much higher BAS activity than that of the wild type PcPKS1 under the conditions of pH 7.0 and pH 9.0, respectively. It provides a theoretical basis for future use of PcPKS1 in genetic engineering to regulate the biosynthesis of flavonoids and raspberry ketones.
Amino Acid Sequence ; Fallopia japonica/metabolism* ; Polyketide Synthases/chemistry* ; Acetone ; Mutagenesis, Site-Directed ; Flavonoids/metabolism* ; Acyltransferases/metabolism*