Characterization and identification of calmodulin and calmodulin binding proteins in hemocyte of the black tiger shrimp (Penaeus monodon)

Mathematical modeling and biochemical analysis support partially ordered calmodulin-myosin light chain kinase binding

Activation of myosin light chain kinase (MLCK) by calcium ions (Ca2+) and calmodulin (CaM) plays an important role in numerous cellular functions including vascular smooth muscle contraction and cellular motility. Despite extensive biochemical analysis, aspects of the mechanism of activation remain controversial, and competing theoretical models have been proposed for the binding of Ca2+ and CaM to MLCK. The models are analytically solvable for an equilibrium steady state and give rise to distinct predictions that hold regardless of the numerical values assigned to parameters. These predictions form the basis of a recently proposed, multi-part experimental strategy for model discrimination. Here we implement this strategy by measuring CaM-MLCK binding using an in vitro FRET system. Interpretation of binding data in light of the mathematical models suggests a partially ordered mechanism for binding CaM to MLCK. Complementary data collected using orthogonal approaches that assess CaM-MLCK binding further support this conclusion.

Characterization and epitope prediction of phosphopyruvate hydratase from Penaeus monodon (black tiger shrimp)

Shellfish allergies constitute an important cause of food-induced anaphylactic reactions, which pose challenges to food safety and human health worldwide. In the present study, the specific IgE (sIgE) binding characteristics of different shrimp proteins of black tiger shrimp (Penaeus monodon) to the sera of eight shrimp-allergic patients from China were studied by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and nanoliquid chromatography time-of-flight mass spectrometry. According to the PLGS scores (>2000) and the sequence coverage (>40%), eight proteins with sIgE binding activity were identified, including myosin heavy chain type 1 (K4Q4N8), hemocyanin (G1AP69 and Q95V28), phosphopyruvate hydratase (O96656), arginine kinase (C7E3T4), tropomyosin (A1KYZ2), sarcoplasmic calcium binding protein (H7CHW2) and glyceraldehyde-3-phosphate dehydrogenase (A0A097BQP2). Among these eight proteins, phosphopyruvate hydratase was a prevalent IgE-binding protein among these Chinese patients with binding observed in 100% of sera. Moreover, 13 peptides were predicted as epitopes of phosphopyruvate hydratase. These new details help us to understand the crustacean IgE-binding proteins especially Penaeus monodon IgE-binding proteins, that would cause allergic reaction to Chinese patients. And our findings may provide essential information to improve allergy prevention and clinical treatment to shrimp allergy in China. PRACTICAL APPLICATION: This research may have diagnostic and therapeutic value for shrimp allergies in China.

Proteomic analysis of individual giant freshwater prawn, Macrobrachium rosenbergii, growth retardants

"Iron prawn" is a condition of severe growth retardation that fishers call. The giant river prawn (Macrobrachium rosenbergii) is a commercially important species contains high protein content and functional nutrients. However, no proteomic information is available for this species. We performed the shotgun 2DLC-MS/MS proteomic analysis of the total protein from "iron prawn". Total 19,758 peptides corresponding to 2613 high-confidence proteins were identified. These proteins range in size from 40 to 70 kDa. KEGG analysis revealed that the largest group consisting total 102 KEGG pathway proteins comparing the "iron prawn" with the normal prawn. Additionally, 7, 11, 1, 6, and 5 commercially important enzymes were found in the eyestalk, liver, muscle, ovary, and testis, respectively. The functions of these differently expressed enzymes include immune system action against pathogens, muscle contraction, digestive system metabolism, cell differentiation, migration, and apoptosis in the severe growth retardation of "iron prawn". Our work provides insight into the understanding of the formation mechanism of "iron prawn".

Toxicological effects of microplastics in Litopenaeus vannamei as indicated by an integrated microbiome, proteomic and metabolomic approach

Microplastics (MPs) are a hazardous pollutant of world concern that threaten aquatic organisms and ecosystems. In this study, we chose the worldwide-distributed shrimp Litopenaeus vannamei as a model and investigated the toxicological effects of five types of MPs on L. vannamei using several omics approaches. After 14 days of exposure to MPs, obvious intestinal microbiota variation was observed, such as increased abundances of Bacteroidetes and Proteobacteria and a decreased abundance of Firmicutes. Specifically, MPs induced several putative opportunistic pathogens and reduced lactic acid- and short-chain fatty acid-producing bacteria. Alternatively, MPs altered haemolymph proteome profiles, but the five types of MPs had different effects on the enriched pathways and the expression of immune-related proteins. Furthermore, MPs also caused haemolymph metabolite variation, especially in amino acid and alpha-linolenic acid metabolism, and 28 differential metabolites were altered in the five MP-treated groups. Changes in intestinal bacteria were correlated with the haemolymph proteins and metabolites of the shrimp. Overall, these results reveal the toxicological effects of MPs on the intestinal microbiota and the host's immunity and metabolism in shrimp.

The Penaeus stylirostris densovirus capsid protein interacts with the Litopenaeus vannamei BCCIP protein

Viral capsid proteins play an important role in the viral infection process. To identify the cellular proteins in shrimp that interact with the Penaeus stylirostris densovirus capsid protein (PstDNV-CP), we constructed a yeast two-hybrid (Y2H) cDNA library of the muscle tissue of Litopenaeus vannamei, and hybridized the bait vector pGBKT7-CP with this library. Cloning and sequencing showed that the shrimp protein interacting with PstDNV-CP was a homolog of BRCA2 and CDKN1A(p21)-interacting protein (BCCIP). We named this protein L. vannamei BCCIP (LvBCCIP). Further analysis showed that LvBCCIP interacted with L. vannamei calmodulin (LvCaM). We validated the interactions between PstDNV-CP and LvBCCIP, and between LvBCCIP and LvCaM, with GST pulldown assays. The gene expression of LvBCCIP increased significantly after PstDNV challenge. In addition, the PstDNV titer of PstDNV-challenged shrimp was significantly reduced after LvBCCIP expression was inhibited using double-stranded RNA (dsRNA) interference. These results indicated that LvBCCIP is critical to PstDNV pathogenesis in L. vannamei. Interestingly, the growth rate of L. vannamei was significantly reduced when LvBCCIP gene expression was silenced, indicating that LvBCCIP may also be associated with growth regulation in L. vannamei. Thus, the interaction between PstDNV-CP and LvBCCIP might explain why PstDNV infection leads to runt-deformity syndrome in shrimp.

Comparison of the ability of mammalian eEF1A1 and its oncogenic variant eEF1A2 to interact with actin and calmodulin

The question as to why a protein exerts oncogenic properties is answered mainly by well-established ideas that these proteins interfere with cellular signaling pathways. However, the knowledge about structural and functional peculiarities of the oncoproteins causing these effects is far from comprehensive. The 97.5% homologous tissue-specific A1 and A2 isoforms of mammalian translation elongation factor eEF1A represent an interesting model to study a difference between protein variants of a family that differ in oncogenic potential. We propose that the different oncogenic impact of A1 and A2 might be explained by differences in their ability to communicate with their respective cellular partners. Here we probed this hypothesis by studying the interaction of eEF1A with two known partners - calmodulin and actin. Indeed, an inability of the A2 isoform to interact with calmodulin is shown, while calmodulin is capable of binding A1 and interferes with its tRNA-binding and actin-bundling activities in vitro. Both A1 and A2 variants revealed actin-bundling activity; however, the form of bundles formed in the presence of A1 or A2 was distinctly different. Thus, a potential inability of A2 to be controlled by Ca2+-mediated regulatory systems is revealed.

Skin mucus proteins of lumpsucker (Cyclopterus lumpus)

Fish skin mucus serves as a first line of defense against pathogens and external stressors. In this study the proteomic profile of lumpsucker skin mucus was characterized using 2D gels coupled with tandem mass spectrometry. Mucosal proteins were identified by homology searches across the databases SwissProt, NCBInr and vertebrate EST. The identified proteins were clustered into ten groups based on their gene ontology biological process in PANTHER (www.patherdb.org). Calmodulin, cystatin-B, histone H2B, peroxiredoxin1, apolipoprotein A1, natterin-2, 14-3-3 protein, alfa enolase, pentraxin, warm temperature acclimation 65 kDa (WAP65kDa) and heat shock proteins were identified. Several of the proteins are known to be involved in immune and/or stress responses. Proteomic profile established in this study could be a benchmark for differential proteomics studies.

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A proteome reference map of lumpsucker skin mucus was established.

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Proteins involved in immune and stress responses were identified in skin mucus of Cyclopterus lumpus.

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Mucosal proteins identified could be potential biomarkers.

Effect of desiccation on oxidative stress and antioxidant response of the black tiger shrimp Penaeus monodon

In the present study, the oxidative stress and antioxidant response in hepatopancreas of the black tiger shrimp Penaeus monodon under desiccation stress were studied, such as activities of antioxidant enzymes (SOD, CAT, GPx and POD), oxidative damage to lipid and protein which indexed by contents of LPO, MDA, protein carbonyl (PC) and ROS production, and the expression of HSP70 and ferritin gene. The duration of desiccation significantly influenced the shrimp survival, and the mortality rates were 10% and 55.0% after desiccation 0.5 h and 3 h, respectively. Compared with the control group, after exposed to desiccation stress, the content of LPO, MDA, PC and ROS production in hepatopancreas increased significantly. SOD, CAT and POD activity in hepatopancreas increased significantly at 0.5 h, but decreased markedly at 1 h. GPx activity in hepatopancreas increased significantly at 0.5 h and 1 h, then decreased significantly at 3 h. The transcript levels of HSP70 and ferritin gene in hepatopancreas increased significantly at 1 h. HE staining showed that desiccation induced damage symptoms in hepatopancreas of P. monodon. These results revealed that desiccation could induce oxidative stress and antioxidant response via confusion of antioxidant enzymes activity and gene transcript level in hepatopancreas of P. monodon, and the time of shrimp under desiccation should lower than 0.5 h.

Oxidative stress response of the black tiger shrimp Penaeus monodon to Vibrio parahaemolyticus challenge

Vibrio parahaemolyticus is a virulent pathogen that affects shrimp aquaculture. Reactive oxygen species are produced by the immune system that defends the host against foreign microorganisms. In the present study, the oxidative stress response in hepatopancreas and gills of Penaeus monodon to V. parahaemolyticus challenge were studied, such as respiratory burst, ROS production (·O2(-) and ·OH), activities of antioxidant enzymes (CAT, GPx, SOD, POD and GST) and oxidative damage to lipid and protein (indexed by contents of MDA). Compared with the control group, after V. parahaemolyticus challenge, respiratory burst and ROS production were up-regulated significantly. GPx and POD activity increased significantly in hepatopancreas and gills of the shrimps at 12 h, but CAT activity decreased markedly at 12 h and 24 h. SOD and GST activity in hepatopancreas of the shrimps increased significantly at 1.5 h, but decreased markedly at 12 h-48 h. MDA content increased significantly after 6 h-24 h challenge. HE staining showed that V. parahaemolyticus challenge induced damage symptoms in hepatopancreas of P. monodon. Our study revealed that V. parahaemolyticus influenced the antioxidative status and caused oxidative stress and tissue damage via confusion of antioxidant enzymes in P. monodon.