title: A novel peroxinectin involved in antiviral and antibacterial immunity of mud crab, Scylla paramamosain.
abstract: Peroxinectin (PX) with cell adhesion and peroxidase activities is important in invertebrate immune responses. We identified a novel PX homolog from Scylla paramamosain (designated as Sp-PX) through transcriptome sequencing. The full-length of cDNA sequence was 3,165 bp. And there was a peroxidase domain in the deduced protein sequence. A cell-adhesive sequence (KGD motif) was also found in the N-terminus. The predicted molecular mass of the mature protein is 83.9 kDa, with an estimated pI of 6.21. At the amino acid level, Sp-PX shared much higher similarities with other crustaceans PX proteins. And Sp-PX also exhibited some similarities with other peroxidase family members. According to real-time polymerase chain reaction, Sp-PX was mainly distributed in the hemocytes. The gene expression levels in the hemocytes of the normal and white spot syndrome virus (WSSV)-challenged crabs were compared via high-throughput RNA sequencing technology, and the results showed that Sp-PX was upregulated at 48 h post-WSSV challenge. Subsequently, how Sp-PX responds to WSSV stimulus was explored through time-course experiments. The Sp-PX transcripts dramatically increased and reached the highest level at 12 h post-injection, whereas Sp-PX transcripts were recovered at 96 h post-challenge. Meanwhile, it was found that the WSSV copies proliferated significantly after a period of latent viral infection for 48 h. In addition,Sp-PX transcripts were also upregulated after Vibrio harveyi or Staphylococcus aureus challenge. Overall, Sp-PX not only participates in antibacterial immunity but also plays a crucial role in the antiviral immune responses of mud crab at the early stage of WSSV infection.
authors.affiliation: The Institute of Bioengineering and Technology, Inner Mongolia University of Science and Technology, Inner Mongolia Autonomous Region, Baotou, 014010, China, nmdzq1981@163.com.
authors.forename: Zhi-Qiang
authors.initials: ZQ
authors.lastname: Du
authors.forename: Qian
authors.initials: Q
authors.lastname: Ren
authors.forename: An-Ming
authors.initials: AM
authors.lastname: Huang
authors.forename: Wen-Hong
authors.initials: WH
authors.lastname: Fang
authors.forename: Jun-Fang
authors.initials: JF
authors.lastname: Zhou
authors.forename: Lu-Jiao
authors.initials: LJ
authors.lastname: Gao
authors.forename: Xin-Cang
authors.initials: XC
authors.lastname: Li
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000276:immunology*; D060829:Arthropod Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D003386:Brachyura / Q000235:genetics / Q000276:immunology / Q000382:microbiology* / Q000821:virology*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D006434:Hemocytes / Q000378:metabolism / Q000382:microbiology / Q000821:virology; D007109:Immunity; D008969:Molecular Sequence Data; D010802:Phylogeny; D016415:Sequence Alignment; D013997:Time Factors; D014018:Tissue Distribution; D046848:White spot syndrome virus 1 / Q000254:growth & development / Q000502:physiology
chemical_list: D000900:Anti-Bacterial Agents; D060829:Arthropod Proteins; D018076:DNA, Complementary