A dicistrovirus increases pupal mortality in Spodoptera frugiperda by suppressing protease activity and inhibiting larval diet consumption

Understanding interactions between viruses and their hosts is conducive to enabling better application of viruses as biocontrol agents.Certain viruses carried by parasitic wasps enhance the parasitic efficiency of wasp-larvae by protecting them against the immune system of their Lepidopteran host.However,the relationship between prey pests and viruses found in predatory natural enemies remains unclear.Herein,we report the interaction between Arma chinensis virus-1(AcV-1),originally isolated from a predatory natural enemy,Arma chinensis(Hemiptera:Pentatomidae),and one of its prey species,Spodoptera frugiperda(Lepidoptera:Noctuidae).The results showed that the AcV-1 virus appeared harmful to the novel host S.frugiperda by inhibiting larval diet consumption and increasing pupal mortality.Meanwhile,sequencing data indicated that the virus altered the gene expression profiles of S.frugiperda.KEGG analysis showed that the proteasome and phagosome pathways related to protein degradation and immune response were significantly enriched.Although the expression levels of digestive enzyme genes did not change significantly,the total protease activity of AcV-1 virus-positive individuals was significantly decreased,suggesting that the virus inhibited diet consumption of S.frugiperda via the down-regulation of digestive enzyme activities.These results indicate that a virus initially isolated in a predatory natural enemy can decrease the fitness of its prey species.The virus was found to impact the host proteasome and phagosome pathways related to protein degradation and immunity,providing a potential mechanism to enhance controlling efficiency.

Ubiquitin-specific protease 21 promotes tumorigenicity and stemness of colorectal cancer by deubiquitinating and stabilizing ZEB1

BACKGROUND Colorectal cancer(CRC)is one very usual tumor together with higher death rate.Ubiquitin-specific protease 21(USP21)has been confirmed to take part into the regulation of CRC progression through serving as a facilitator.Interestingly,the promotive function of USP21 has also discovered in the progression of CRC.ZEB1 has illustrated to be modulated by USP7,USP22 and USP51 in cancers.However,the regulatory functions of USP21 on ZEB1 in CRC progression need more invest-igations.AIM To investigate the relationship between USP21 and ZEB1 in CRC progression.METHODS The mRNA and protein expressions were assessed through RT-qPCR,western blot and IHC assay.The interaction between USP21 and ZEB1 was evaluated through Co-IP and GST pull down assays.The cell proliferation was detected through colony formation assay.The cell migration and invasion abilities were determined through Transwell assay.The stemness was tested through sphere formation assay.The tumor growth was evaluated through in vivo mice assay.RESULTS In this work,USP21 and ZEB1 exhibited higher expression in CRC,and resulted into poor prognosis.Moreover,the interaction between USP21 and ZEB1 was further investigated.It was demonstrated that USP21 contributed to the stability of ZEB1 through modulating ubiquitination level.In addition,USP21 streng-thened cell proliferation,migration and stemness through regulating ZEB1.At last,through in vivo assays,it was illustrated that USP21/ZEB1 axis aggravated tumor growth.CONCLUSION For the first time,these above findings manifested that USP21 promoted tumorigenicity and stemness of CRC by deubiquitinating and stabilizing ZEB1.This discovery suggested that USP21/ZEB1 axis may provide novel sights for the treatment of CRC.

Elucidation of potential relationship between endogenous proteases and key flavor substances in dry-cured pork coppa

Dry-cured meat products are considerably popular around the world due to unique flavor.Proteolysis is one of the enzymatic reactions from which flavor substances are derived,which is affected by endogenous proteases.The purpose aimed to reveal the potential relationship between endogenous proteases and key flavor substances in dry-cured pork coppa in this paper.The dynamic changes of endogenous proteases activity,free amino acids,and volatiles during dry-cured pork coppa processing were characterized.The results showed that 5 kinds of free amino acids,Glu,Lys,Val,Ala,and Leu,were identified as significant contributors to taste.Meanwhile,key volatiles,such as hexanal,nonanal,octanal,benzaldehyde,3-methyl butanoic acid,2-methyl propanoic acid,and ethyl octanoate,greatly contributed to the flavor characteristics of dry-cured pork coppa.Further partial correlation analysis was performed to better elucidate the relationship among parameters.The results revealed that close relationship between endogenous proteases and key substances.RAP not only significantly affected the accumulation of key active-amino acids,but also affected the accumulation of ethyl octanoate,2,3-pentanedione,and 2,3-octanedione by regulating the accumulation of octanoic acid and Leu.In addition,cathepsin B and D,DPP II,DPP IV and RAP notably affected accumulation of hexanal.

Roles of host proteases in the entry of SARS-CoV-2

The spike protein(S)of SARS-CoV-2 is responsible for viral attachment and entry,thus a major factor for host suscep-tibility,tissue tropism,virulence and pathogenicity.The S is divided with S1 and S2 region,and the S1 contains the receptor-binding domain(RBD),while the S2 contains the hydrophobic fusion domain for the entry into the host cell.Numerous host proteases have been implicated in the activation of SARS-CoV-2 S through various c leavage sites.In this article,we review host proteases including furin,trypsin,transmembrane protease serine 2(TMPRSS2)and cathepsins in the activation of SARS-CoV-2 S.Many betacoronaviruses including SARS-CoV-2 have polybasic residues at the S1/S2 site which is subjected to the cleavage by furin.The S1/S2 cleavage facilitates more assessable RBD to the receptor ACE2,and the binding triggers further conformational changes and exposure of the S2'site to proteases such as type Il transmembrane serine proteases(TTPRs)including TMPRSS2.In the presence of TMPRSS2 on the target cells,SARS-CoV-2 can utilize a direct entry route by fusion of the viral envelope to the cellular membrane.In the absence of TMPRSS2,SARS-CoV-2 enter target cells via endosomes where multiple cathepsins cleave the S for the successful entry.Additional host proteases involved in the cleavage of the S were discussed.This article also includes roles of 3C-like protease inhibitors which have inhibitory activity against cathepsin L in the entry of SARS-CoV-2,and discussed the dual roles of such inhibitors in virus replication.

Transmembrane serine protease 4 expression in the prognosis of radical resection for biliary tract cancer

BACKGROUND Recent advancements in biliary tract cancer(BTC)treatment have expanded beyond surgery to include adjuvant therapy,yet the prognosis remains poor.Identifying prognostic biomarkers could enhance the assessment of patients who have undergone radical resection for BTC.AIM To determine transmembrane serine protease 4(TMPRSS4)utility as a prognostic biomarker of radical resection for BTC.METHODS Medical records of patients who underwent radical resection for BTC,excluding intrahepatic cholangiocarcinoma,were retrospectively reviewed.The associations between TMPRSS4 expression and clinicopathological factors,overall survival,and recurrence-free survival were analyzed.RESULTS Among the 85 patients undergoing radical resection for BTC,46(54%)were TMPRSS4-positive.The TMPRSS4-positive group exhibited significantly higher preoperative carbohydrate antigen 19-9(CA19-9)values and greater lymphatic invasion than the TMPRSS4-negative group(P=0.019 and 0.039,respectively).Postoperative overall survival and recurrence-free survival were significantly worse in the TMPRSS4-positive group(median survival time:25.3 months vs not reached,P<0.001;median survival time:28.7 months vs not reached,P=0.043,respectively).Multivariate overall survival analysis indicated TMPRSS4 positivity,pT3/T4,and resection status R1 were independently associated with poor prognosis(P=0.032,0.035 and 0.030,respectively).TMPRSS4 positivity correlated with preoperative CA19-9 values≥37 U/mL and pathological tumor size≥30 mm(P=0.016 and 0.038,respectively).CONCLUSION TMPRSS4 is a potential prognostic biomarker of radical resection for BTC.

Regulation of intestinal permeability: The role of proteases

The gastrointestinal barrier is-with approximately 400 m^2-the human body's largest surface separating the external environment from the internal milieu. This barrier serves a dual function: permitting the absorption of nutrients, water and electrolytes on the one hand, while limiting host contact with noxious luminal antigens on the other hand. To maintain this selective barrier, junction protein complexes seal the intercellular space between adjacent epithelial cells and regulate the paracellular transport. Increased intestinal permeability is associated with and suggested as a player in the pathophysiology of various gastrointestinal and extraintestinal diseases such as inflammatory bowel disease, celiac disease and type 1 diabetes. The gastrointestinal tract is exposed to high levels of endogenous and exogenous proteases, both in the lumen and in the mucosa. There is increasing evidence to suggest that a dysregulation of the protease/antiprotease balance in the gut contributes to epithelial damage and increased permeability. Excessive proteolysis leads to direct cleavage of intercellular junction proteins, or to opening of the junction proteins via activation of protease activated receptors. In addition, proteases regulate the activity and availability of cytokines and growth factors, which are also known modulators of intestinal permeability. This review aims at outlining the mechanisms by which proteases alter the intestinal permeability. More knowledge on the role of proteases in mucosal homeostasis and gastrointestinal barrier function will definitely contribute to the identification of new therapeutic targets for permeability-related diseases.

Family-level diversity of extracellular proteases of sedimentary bacteria from the South China Sea

Protease-producing bacteria and their extracellular proteases are key players in degrading organic nitrogen to drive marine nitrogen cycling and yet knowledge on both of them is still very limited. This study screened protease-producing bacteria from the South China Sea sediments and analyzed the diversity of their extracellular proteases at the family level through N-terminal amino acid sequencing. Results of the 16 S rRNA gene sequence analysis showed that all screened protease-producing bacteria belonged to the class Gammaproteobacteria and most of them were affiliated with different genera within the orders Alteromonadales and Vibrionales. The Nterminal amino acid sequence analysis for fourteen extracellular proteases from fourteen screened bacterial strains revealed that all these proteases belonged to the M4 family of metalloproteases or the S8 family of serine proteases. This study presents new details on taxa of marine sedimentary protease-producing bacteria and types of their extracellular proteases, which will help to comprehensively understand the process and mechanism of the microbial enzymatic degradation of marine sedimentary organic nitrogen.

STRUCTURE-FUNCTION FEATURES AND EFFECTS ON BLOOD COAGULATION OF SNAKE VENOM SERINE PROTEASES*

Snake venoms,especially those from the two subfamilies,Crotalinae and Viperinae,contained a lot of serine proteases. They were responsible for the hemorrhage,shock,or disorder of blood coagulation after envenomation. They acted,by activating,inactivating,or other converting effects,on almost all the components of hemostatic and fibrinolytic systems. Their sequences were homologous to trypsin-kallikrein serine proteases. Variation of primary sequences out of active center results in the difference of substrate specificities and the further difference of biological and pharmacological activities. Because of their common and unique properties compared to their physiological corresponding factors,snake venom proteases are proved to be an excellent model for the study of protease substrate discriminating mechanism. Furthermore,they have found an important position both in basic research and application of hemostasis and thrombosis in clinic.

Effects of Different Light Qualities on Activity and Gene Expression of Caspase-like Proteases in Tobacco Leaves

[Objective] The study aimed to investigate the activity and gene expression of caspase-like proteases in tobacco leaves growing under different light qualities. [Method] By covering tobacco plants with white, red, yellow, blue and purple films to obtain different light quality, the changes of chlorophyll content, activity and gene expression of caspase-like proteases in the tobacco leaves were studied. [Results] Compared with treatments of white, red and yellow film, blue and purple films delayed the decrease of chlorophyll content and senescence of tobacco leaves at the late growth stage, and relatively lowered the activity and gene expression of caspase-like proteases during growth, development and senescence periods. [Conclusion] Different light qualities exhibited various effects on the growth, development and senescence of tobacco leaves, possibly by affecting the activity and gene expression of caspase-like proteases to some extent.

Visceral hypersensitivity in inflammatory bowel diseases and irritable bowel syndrome: The role of proteases

Proteases, enzymes catalyzing the hydrolysis of peptide bonds, are present at high concentrations in the gastrointestinal tract. Besides their well-known role in the digestive process, they also function as signaling molecules through the activation of protease-activated receptors(PARs). Based on their chemical mechanism for catalysis, proteases can be classified into several classes: serine, cysteine, aspartic, metallo- and threonine proteases represent the mammalian protease families. In particular, the class of serine proteases will play a significant role in this review. In the last decades, proteases have been suggested to play a key role in the pathogenesis of visceral hypersensitivity, which is a major factor contributing to abdominal pain in patients with inflammatory bowel diseases and/or irritable bowel syndrome. So far, only a few preclinical animal studies have investigated the effect of protease inhibitors specifically on visceral sensitivity while their effect on inflammation is described in more detail. In our accompanying review we describe their effect on gastrointestinal permeability. On account of their promising results in the field of visceral hypersensitivity, further research is warranted. The aim of this review is to give an overview on the concept of visceral hypersensitivity as well as on the physiological and pathophysiological functions of proteases herein.

Construction of Midgut Tissue-Specific cDNA Library of Bombyx mandarina M. and Isolation and Sequence Analysis of Serine Protease Gene Fragment

[Objective] The aim of the study is to construct cDNA library of midgut tissue of wild silkworm and isolate the serine protease gene. [Method] The midgut tissue-specific cDNA library of wild silkworm was constructed via cDNA Library Construction Kit (TaKaRa), then the serine protease gene was cloned via sequencing of the yielded cDNA library. [Result] The titer of cDNA library reached 6.2×105 pfu/ml, average insert size was about 1.2 kb. The serine protease gene cDNA fragment was obtained from colony sequencing (Accession No: EU672968). The nucleotide sequence of the cloned 854 bp fragment encodes 284 amino acid residues. Homology analyses showed some homology between putative amino acid sequence of the cloned fragment and amino acid sequences of serine proteases from other ten insects. [Conclusion] The results may avail to reveal the resistance of silkworm and wild silkworm to exotic intrusion.

Purification of Extracellular Protease Produced by Rhizoctonia solani and Its Partial Characterization

[Objective] The aim of the study was to provide the basis for researching the pathogenicity mechanism of Rhizoctonia solani.[Method] The extracellular protease was purified after ammonium sulfate precipitation through DEAE-Sephrase Fast Flow,Phenyl-Sepharose Fast Flow and Sephadex G-75 ch rom atography. [Result] The extracellular protease with molecular weight of 49.5 ku was obtained from fermentation liquid of R. solani. The optimal temperature and pH value for its activity were 6.4 and 30 ℃ respectively. Zn^2＋,Fe^3＋,Cu^2＋had inhibition on enzyme activity,while Mg^2＋,Mn^2＋had no effect on enzyme activity,and Ca^2＋ could activate enzymatic activity in low concentration.[Conclusion] R. solani could secrete extracellular protease,but the relationship between the extracellular protease and the pathogenicity of R. solani required further study.

Effect of Metal Ions on Protease Activities in the Intestines and Hepatopancreas of Red-white Ornamental Carp (Cyprinus carpio L)

[Objective] The aim of this study was to study effects of metal ions on the protease activities in digestive tissues and gland of red-white ornamental carp（Cyprinus carpio L）.[Method] Effects of four kinds of metal ions （K＋,Na＋,Mg2＋ and Ca2＋） on protease activities in hepatopancreas,foregut,midgut,hindgut of red-white ornamental carp were studied by enzyme analysis method.[Result] Effects of four kinds of metal ions on protease activities of red-white ornamental carp were different in the range of experimental concentration from 25 mmol/L to 150 mmol/L.K＋ could promote protease activities in hepatopancreas and hindgut at different levels.Especially,K＋ had the promoting effect at low-concentration level,but the inhibitory effect at high-concentration level in midgut and the inhibitory effect in foregut.Na＋ had the promoting effect on protease activities in hepatopancreas,foregut and hindgut at different levels,but the inhibitory effect in midgut.Mg2＋ and Ca2＋ had the inhibitory effect on protease activities in intestinal and hepatopancreas at different levels.[Conclusion] This study provides basic data and theoretical foundation for researches on the digestive physiology of red-white ornamental carp or the development and optimization of compound feed.

Properties of Alkaline Protease Produced by Strain Ⅰ13

[Objective] This study aimed to investigating properties of alkaline protease produced by strain Ⅰ 13.[Method] Crude enzyme of alkaline protease was obtained from alkaline protease produced by strain I 13,while effects of temperature and pH value on enzyme activity were also investigated in this study.[Result] The optimal temperature of alkaline protease produced by strain Ⅰ 13 was 40 ℃,while enzyme activity maintains a higher level from 30 to 60 ℃ and over 40% of the largest enzyme activity still maintained within the range from 20 to 30 ℃.The optimal pH value was 10.5,and over 90% of the largest enzyme activity still maintained within the range from 8.0 to 11.0,which had broader pH value spectrum.[Conclusion] This alkaline protease has huge potential to be developed into washing-powder additive.

The Technology Research of Anti-oxidation Peptide Preparation by Alkaline Protease Hydrolyzing Wheat Germ Meal

Wheat germ meal is the by production of oil extracting, and a great quantity of it has been wasted, thus the quantity of lost protein is great. In order to use wheat germ meal proteins adequately, wheat germ proteins were hydrolyzed to anti-oxidation peptides by using alkaline protease. Through the single factor analysis and regression analysis, the optimized experiment conditions of hydrolysising wheat germ meal to wheat germ peptides were enzymatic quantity 0.8%（w/w）, material to liquid ratio 1∶12.3, enzymolysis time 2.1 h. Under these conditions, the scavenging effect was 49.78%,the DH was 22% and peptides content in enzymatic hydrolysate was 1.9%（w/w）.By SDS-PAGE electrophoresis,the molecular weight range of wheat germ peptides were below 10 ku and most were between 4.54 and 5.63 ku.The wheat germ proteins could be used ful y and grain resources would be saved.

Inhibition of cysteine protease papain by metal ions and polysulfide complexes,especially mercuric ion

Aim Cysteine proteases are closely associated with many human and non-human pathological processes and are potential targets for metal ions especially Hg^2＋ and the related species. In the present work, on the basis of to the general study on the effects of some metal ions on the activity of papain, a well-known representative of cysteine protease family, the inhibitory effects of Hg^2＋ and polysulfide complexes were studied. Results All the metal ions tested （Hg^2＋, Cu^2＋, Ag^＋, Au^3＋, Zn^2＋, Cd^2＋, Fe^3＋, Mn^2＋, Pb^2＋, Yb^3＋） inhibit the activity of papain anda good correlation between the inhibitory potency and softness-and-hardness was observed. Among the metals, Hg^2＋ was shown to be a potent inhibitor of papain with a Kiof 2 × 10^-7 mol·L^-1 among. Excessive amounts of glutathione and cysteine could reactivate the enzyme activity of papain deactivated by Hg^2＋. These evidences supported that Hg^2＋ might bind to the catalytic site of papain. Interestingly, Hg （Ⅱ） polysulfide complexes were for the first time found to inhibit papain with a Ki of 7 × 10^-6 mol·L^-1, whose potency is close to a well known mercury compound, thimerosal （Ki=2.7 × 10^-6）. In addition, Hg （Ⅱ） polysulfide complexes exhibit good permeability （ 1.9 × 10-5 cm· s^-1） to caco-2 monolayer. Conclusion These results suggested that mercury polysulfide complexes might be potential bioactive species in the interaction with cysteine proteases and other- SH-content proteins, providing a new clue to understand the mechanism of the toxicological and pharmacological actions of cinnabar and other insoluble mercury compounds.

Screening of Protease Inhibitory Activity in Aqueous Extracts of Marine Invertebrates from Cuban Coast

Protease inhibitors have been isolated from many variable sources;however, the need to identify and characterize new molecules has increased with the discovery of new therapeutic targets and the lack of specificity of already identified compounds with inhibitory activity. The goal of this work was to search for inhibitory activity against four proteolytic enzymes already recognized as therapeutic targets: human neutrophil elastase, dipeptidyl peptidase IV, subtilisin from Bacillus licheniformis and cathepsin K in selected marine invertebrates from the Caribbean Sea. A systematic screening was carried out with selected aqueous extracts belonging to 20 species from seven different phyla: Annelida, Bryozoa, Chordata, Cnidaria, Equinodermata, Mollusca and Porifera, all collected at the coast of Havana (Cuba). All extracts showing initial inhibitory activity were characterized in terms of IC50 values and specific inhibitory activity (SIA). Model enzymes were used in the case of human neutrophil elastase (porcine pancreatic elastase) and cathepsin K (papain) for the screening and all positive results were confirmed by testing toward the therapeutic targets. Ten extracts were identified showing inhibitory activity against human neutrophil elastase, for which the most promising values were obtained for Nerita peloronta. Only one extract, Bunodosoma granulifera, showed inhibitory activity against dipeptidyl peptidase IV with rather poor values of IC50 and SIA. Seven extracts showed inhibitory activity against B. licheniformis subtilisin with very good IC50 and SIA values for Lissodendorix isodyctialis, Cenchritis muricatus, and N. peloronta. Finally, eight extracts were positive for cathepsin K with almost similar parameters values among them. All these results confirmed the richness and potential of the marine invertebrate’s fauna and indicated new promising sources for the identification of natural compounds with potential application in therapeutics.

Purification and Biochemical Characterization of a Protease Inhibitor Ⅱ Family from Jalapeno Pepper(Capsicum annuum L.)

Capsicum annuum L. was initially domesticated in Mexico and northern Central America, and represented an ancient Neotropical plant food complex. The purpose of this paper is to report the isolation and purification of a novo-member of a protease inhibitor from jalape&ntildeo pepper (Capsicum annuum L.) (PIJP). The molecular weight of PIJP inhibitor is 5.95 kDa with 56 amino acids and 6 Cys residues with high inhibitory activity to trypsin with a Ki value of 95 nM. This inhibitor according to the alignment with homologous from NCBI and Pfam databases is a member of proteinase inhibitors II. It is worthwhile to mention a major compositional difference between the proteinase inhibitor II families which have 8 Cys residues. PIJP is the first purified proteinase inhibitor, member of this family with only 6 Cys residues.

Novel mutations in ubiquitin-specific protease 26 gene might cause spermatogenesis impairment and male infertility

Aim： To study the incidence of single nucleotide polymorphisms in ubiquitin-specific protease 26 （USP26） gene and its involvement in idiopathic male infertility in China. Methods： Routine semen analysis was performed. Infertility factors such as immunological, infectious and biochemical disorders were examined to select patients with idiopathic infertility. DNA was isolated from peripheral blood of the selected patients and control population, which were examined for mutations using polymerase chain reaction-single strand conformation polymorphism analysis. Furthermore, nucleotide sequences were sequenced in some patients and controls. Results： Of 41 infertile men, 9 （22.0%, P = 0.01） had changes in USP26 gene on the X chromosome. A compound mutation （364insACA; 460G→A） was detected in 8 patients （19.5%, P = 0.01） and a 1044T→A substitution was found in 1 patient （2.4%, P 〉 0.05）. All three variations led to changes in the coding amino acids. Two substitutions predict some changes： 460G→ A changes a valine into an isoleucine, and 1044T → A substitutes a leucine for a phenylalanine. Another insertion of three nucleotides ACA causes an insertion of threonine. No other changes were found in the remaining patients and fertile controls. Conclusion： The USP26 gene might be of importance in male reproduction. Mutations in this gene might be associated with male infertility, and might negatively affect testicular function. Further research on this issue is in progress.

Enteric bacterial proteases in inflammatory bowel diseasepathophysiology and clinical implications

Numerous reports have identified a dysbiosis in the intestinal microbiota in patients suffering from inflammatory bowel diseases(IBD),yet the mechanism(s)in which this complex microbial community initiates or perpetuates inflammation remains unclear.The purpose of this review is to present evidence for one such mechanism that implicates enteric microbial derived proteases in the pathogenesis of IBD.We highlight and discuss studies demonstrating that proteases and protease receptors are abundant in the digestive system.Additionally,we investigate studies demonstrating an association between increased luminal protease activity and activation of protease receptors,ultimately resulting in increased intestinal permeability and exacerbation of colitis in animal models as well as in human IBD.Proteases are essential for the normal functioning of bacteria and in some cases can serve as virulence factors for pathogenic bacteria.Although not classified as traditional virulence factors,proteases originating from commensal enteric bacteria also have a potential association with intestinal inflammation via increased enteric permeability.Reports of increased protease activity in stools from IBD patients support a possible mechanism for a dysbiotic enteric microbiota in IBD.A better understanding of these pathways and characterization of the enteric bacteria involved,their proteases,and protease receptors may pave the way for new therapeutic approaches for these diseases.