title: Crustins from eyestalk cDNA library of swimming crab Portunus trituberculatus: molecular characterization, genomic organization and expression analysis.
abstract: Crustins are cationic, cysteine-rich antimicrobial proteins, containing a single whey acidic protein (WAP) domain in the C-terminal end. Different from the reported Ptcrustin in the hemocytes, two novel crustin genes (PtCrustin2 and PtCrustin3) were cloned completely from the eyestalk cDNA library of Portunus trituberculatus in this study. All PtCrustins share the consensus cysteine motif and are considered as Type I crustins. Four exons and three introns are identified in genomic DNA sequence of PtCrustin3 while three exons and two introns in PtCrustin2. The mRNA transcripts of PtCrustin2 and PtCrustin3 are mainly detected in eyestalk and gills, but not in hemocytes. Although both PtCrutins are up-regulated after challenge of three microorganisms, PtCrustin3 seems to respond more quickly to microbial challenge than Ptcrustin2. Unlike most crustins, both recombinant PtCrustin2 and PtCrustin3 exhibit antibacterial activity against Gram-positive bacteria Micrococcus luteus and Staphyloccocus aureus and Gram-negative bacterium Pseudomonas aeruginosa. In addition, rPtCrustin2 is moderately active against yeast Pichia pastoris and rPtCrustin3 show significant activity against Gram-negative bacterium Vibrio alginolyticus. These results indicate that PtCrustin2 and PtCrustin3 are two novel crustins and play different roles in immune response of P. trituberculatus against microbial challenge.
authors.affiliation: EMBL, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, China. zhxcui@yahoo.com.cn
authors.forename: Zhaoxia
authors.initials: Z
authors.lastname: Cui
authors.forename: Chengwen
authors.initials: C
authors.lastname: Song
authors.forename: Yuan
authors.initials: Y
authors.lastname: Liu
authors.forename: Shuangyan
authors.initials: S
authors.lastname: Wang
authors.forename: Qianqian
authors.initials: Q
authors.lastname: Li
authors.forename: Xihong
authors.initials: X
authors.lastname: Li
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry / Q000235:genetics* / Q000276:immunology* / Q000378:metabolism; D060829:Arthropod Proteins / Q000737:chemistry / Q000235:genetics* / Q000276:immunology*; D001483:Base Sequence; D003386:Brachyura / Q000235:genetics* / Q000276:immunology*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D005123:Eye / Q000378:metabolism; D020869:Gene Expression Profiling / Q000662:veterinary; D005786:Gene Expression Regulation; D015723:Gene Library; D006434:Hemocytes / Q000378:metabolism; D016982:Micrococcus luteus / Q000502:physiology; D008969:Molecular Sequence Data; D010843:Pichia / Q000502:physiology; D020033:Protein Isoforms / Q000235:genetics / Q000276:immunology; D011550:Pseudomonas aeruginosa / Q000502:physiology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary; D016415:Sequence Alignment / Q000662:veterinary; D013211:Staphylococcus aureus / Q000502:physiology; D044149:Vibrio alginolyticus / Q000502:physiology
chemical_list: D023181:Antimicrobial Cationic Peptides; D060829:Arthropod Proteins; D018076:DNA, Complementary; D020033:Protein Isoforms; D012333:RNA, Messenger