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Träfflista för sökning "L773:0021 9258 ;pers:(Söderhäll Kenneth)"

Sökning: L773:0021 9258 > Söderhäll Kenneth

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1.
  • Huang, TS, et al. (författare)
  • A cell adhesion protein from the crayfish Pacifastacus leniusculus, a serine proteinase homologue similar to Drosophila masquerade
  • 2000
  • Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 275:14, s. 9996-10001
  • Tidskriftsartikel (refereegranskat)abstract
    • A cDNA encoding a protein resembling masquerade, a serine proteinase homologue expressed during embryogenesis, larval, and pupal development in Drosophila melanogaster, was identified in hemocytes of the adult freshwater crayfish, Pacifastacus leniusculus. The crayfish protein is similar to Drosophila masquerade in the following aspects: (a) overall sequence of the serine proteinase domain, such as the position of three putative disulfide bridges, glycine in the place of the catalytic serine residue, and the presence of a substrate-lining pocket typical for trypsins; (b) the presence of several copies of a disulfide-knotted motif in the putative propeptide. This masquerade-like protein is cleaved into a 27-kDa fragment, which could be detected by immunoblot analysis using an affinity-purified antibody against a synthetic peptide in the C-terminal domain of the protein. The 27-kDa protein could be immunoaffinity-purified from hemocyte lysate supernatant and exhibited cell adhesion activity in vitro, indicating that the C-terminal domain of the crayfish masquerade-like protein mediates cell adhesion.
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2.
  • Junkunlo, Kingkamon, et al. (författare)
  • Reactive oxygen species affect transglutaminase activity and regulate hematopoiesis in a crustacean
  • 2016
  • Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 291:34, s. 17593-17601
  • Tidskriftsartikel (refereegranskat)abstract
    • Reactive oxygen species (ROS) serve as a prime signal in the commitment to hematopoiesis in both mammals and Drosophila. In this study, the potential function of ROS during hematopoiesis in the crayfish Pacifastacus leniusculus was examined. The antioxidant N-acetylcysteine (NAC) was used to decrease ROS in both in vivo and in vitro experiments. An increase in ROS was observed in the anterior proliferation center (APC) after LPS injection. In the absence of NAC, the LPS-induced increase in ROS levels resulted in the rapid restoration of the circulating hemocyte number. In the presence of NAC, a delay in the recovery rate of the hemocyte number was observed. NAC treatment also blocked the spread of APC and other hematopoietic tissue (HPT) cells, maintaining these cells at an undifferentiated stage. Extracellular transglutaminase (TGase) has been shown previously to play a role in maintaining HPT cells in an undifferentiated form. In this study, we show that extracellular TGase activity increased when the ROS level in HPT or APC cells was reduced after NAC treatment. In addition, collagen, a major component of the extracellular matrix and a TGase substrate were co-localized on the HPT cell surface. Taken together, the results of this study show that ROS are involved in crayfish hematopoiesis, in which a low ROS level is required to maintain hematopoietic progenitor cells in the tissue and to reduce hemocyte release. The potential roles of TGase in this process are investigated and discussed.
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3.
  • Junkunlo, Kingkamon, et al. (författare)
  • Transglutaminase inhibition stimulates hematopoiesis and reduces aggressive behavior of crayfish, Pacifastacus leniusculus
  • 2019
  • Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; :2, s. 708-715
  • Tidskriftsartikel (refereegranskat)abstract
    • Transglutaminase (TGase) is a Ca2+-dependent cross-linking enzyme, which has both enzymatic and nonenzymatic properties. TGase is involved in several cellular activities, including adhesion, migration, survival, apoptosis, and extracellular matrix (ECM) organization. In this study, we focused on the role of the TGase enzyme in controlling hematopoiesis in the crayfish, Pacifastacus leniusculus. We hypothesized that a high TGase activity could mediate an interaction of progenitor cells with the ECM to maintain cells in an undifferentiated stage in the hematopoietic tissue (HPT). We found here that the reversible inhibitor cystamine decreases the enzymatic activity of TGase from crayfish HPT, as well as from guinea pig, in a concentration-dependent manner. Cystamine injection decreased TGase activity in HPT without affecting production of reactive oxygen species. Moreover, the decrease in TGase activity in the HPT increased the number of circulating hemocytes. Interestingly the cystamine-mediated TGase inhibition reduced aggressive behavior and movement in crayfish. In conclusion, we show that cystamine-mediated TGase inhibition directly releases HPT progenitor cells from the HPT into the peripheral circulation in the hemolymph and strongly reduces aggressive behavior in crayfish.
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4.
  • Kim, Chan-Hee, et al. (författare)
  • A three-step proteolytic cascade mediates the activation of the peptidoglycan-induced toll pathway in an insect
  • 2008
  • Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 283:12, s. 7599-7607
  • Tidskriftsartikel (refereegranskat)abstract
    • The recognition of lysine-type peptidoglycans (PG) by the PG recognition complex has been suggested to cause activation of the serine protease cascade leading to the processing of Spätzle and subsequent activation of the Toll signaling pathway. So far, two serine proteases involved in the lysine-type PG Toll signaling pathway have been identified. One is a modular serine protease functioning as an initial enzyme to be recruited into the lysine-type PG recognition complex. The other is the Drosophila Spätzle processing enzyme (SPE), a terminal enzyme that converts Spätzle pro-protein to its processed form capable of binding to the Toll receptor. However, it remains unclear how the initial PG recognition signal is transferred to Spätzle resulting in Toll pathway activation. Also, the biochemical characteristics and mechanism of action of a serine protease linking the modular serine protease and SPE have not been investigated. Here, we purified and cloned a novel upstream serine protease of SPE that we named SAE, SPE-activating enzyme, from the hemolymph of a large beetle, Tenebrio molitor larvae. This enzyme was activated by Tenebrio modular serine protease and in turn activated the Tenebrio SPE. The biochemical ordered functions of these three serine proteases were determined in vitro, suggesting that the activation of a three-step proteolytic cascade is necessary and sufficient for lysine-type PG recognition signaling. The processed Spätzle by this cascade induced antibacterial activity in vivo. These results demonstrate that the three-step proteolytic cascade linking the PG recognition complex and Spätzle processing is essential for the PG-dependent Toll signaling pathway.
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7.
  • Lin, Xionghui, 1976-, et al. (författare)
  • Ancient Cytokines, the Role of Astakines as Hematopoietic Growth Factors
  • 2010
  • Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 285:37, s. 28577-28586
  • Tidskriftsartikel (refereegranskat)abstract
    • Hematopoiesis is the process by which hemocytes mature and subsequently enter the circulation. Vertebrate prokineticins (PKs) are known to take part in this process, as are the invertebrate prokineticin domain proteins, astakines. In Pacifastacus leniusculus, astakine 1 is essential for the release of new hemocytes into the open circulatory system of these animals. In addition to astakine 1, we have now cloned a homologue of astakine 1 with an insert of 13 amino acids, named as astakine 2. Both crustacean astakines lack the N-terminal AVIT motif, which is present in vertebrate PKs, and hence receptor binding differs from that of vertebrate PKs. We have found astakine-like sequences in 19 different invertebrate species, and the sequences show that some motifs are conserved among invertebrate groups. Previously we showed that astakine 1 is directly involved in hematopoiesis, and now we show that astakine 1 and astakine 2 have different roles in hemocyte lineage differentiation. Astakine 1 can stimulate proliferation of hematopoietic tissue (Hpt) cells (precursor of hemocytes) as well as specifically induce differentiation of Hpt cells along the semigranular cell lineage, whereas astakine 2 plays a role in granular cell differentiation. Moreover, we discuss the impact of the putative structures of different astakines in comparison with the vertebrate prokineticins.
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9.
  • Liu, Haipeng, et al. (författare)
  • Phenoloxidase is an important component of the defense against Aeromonas hydrophila infection in a crustacean, Pacifastacus leniusculus
  • 2007
  • Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 282:46, s. 33593-33598
  • Tidskriftsartikel (refereegranskat)abstract
    • The melanization cascade, in which phenoloxidase is the terminal enzyme, appears to play a key role in recognition of and defense against microbial infections in invertebrates. Here, we show that phenoloxidase activity and melanization are important for the immune defense toward a highly pathogenic bacterium, Aeromonas hydrophila, in the freshwater crayfish, Pacifastacus leniusculus. RNA interference-mediated depletion of crayfish prophenoloxidase leads to increased bacterial growth, lower phagocytosis, lower phenoloxidase activity, lower nodule formation, and higher mortality when infected with this bacterium. In contrast, if RNA interference of pacifastin, an inhibitor of the crayfish prophenoloxidase activation cascade, is performed, it results in lower bacterial growth, increased phagocytosis, increased nodule formation, higher phenoloxidase activity, and delayed mortality. Our data therefore suggest that phenoloxidase is required in crayfish defense against an infection by A. hydrophila, a highly virulent and pathogenic bacterium to crayfish.
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10.
  • Prapavorarat, Adisak, et al. (författare)
  • A Novel Viral Responsive Protein Is Involved in Hemocyte Homeostasis in the Black Tiger Shrimp, Penaeus monodon
  • 2010
  • Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 285:28, s. 21467-21477
  • Tidskriftsartikel (refereegranskat)abstract
    • A novel viral responsive protein, namely hemocyte homeostasis-associated protein (HHAP), was characterized for its role in the response of shrimp to white spot syndrome virus infection. The full-length cDNAs of HHAP from the black tiger shrimp (PmHHAP), Penaeus monodon, and the fresh water crayfish (PlHHAP), Pacifastacus leniusculus, were obtained and showed high sequence identity to a hypothetical protein from various organisms, with the highest identity to the hypothetical protein TcasGA2_TC006773 from the red flour beetle, Tribolium castaneum (54% amino acid sequence identity). Transcripts of PmHHAP were expressed in various shrimp tissues with the highest expression in hematopoietic tissue, whereas the transcripts of PlHHAP were found in the hematopoietic and nerve tissues. Upon white spot syndrome virus infection, a high up-regulation level of shrimp hemocytic HHAP mRNA and protein was observed by real-time reverse transcription-PCR and immunofluorescence microscopy, respectively. Gene silencing of PmHHAP by RNA interference resulted in a significant decrease in the number of circulating hemocytes and 100% shrimp mortality within 30 h of the double-stranded PmHHAP RNA injection (but not in control shrimp), indicating that HHAP is essential for shrimp survival. Interestingly, severe damage of hemocytes was observed in vivo in the PmHHAP knockdown shrimp and in vitro in shrimp primary hemocyte cell culture, suggesting that PmHHAP plays an important role in hemocyte homeostasis. Thus, it is speculated that the up-regulation of PmHHAP is an important mechanism to control circulating hemocyte levels in crustaceans during viral infection.
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