title: A Lysin motif (LysM)-containing protein functions in antibacterial responses of red swamp crayfish, Procambarus clarkii.
abstract: Lysin domain (LysM) is a widely spread domain in nature and could bind different peptidoglycans and chitin-like compounds in bacteria and eukaryotes. In plants, Lysin motif containing proteins are one of the major classes of pattern recognition proteins which can recognize GlcNAc-containing glycans and have important functions in plant immunity. However, their functions in animal immunity are still unclear. In this study, a cDNA encoding a LysM containing protein was identified from red swamp crayfish, Procambarus clarkii. The cDNA of PcLysM contained 1200 base pair nucleotides with an open reading frame of 702bp encoding a protein of 233 amino acid residues. The deduced protein had a calculated molecular mass of 25.950kDa and a pI of 6.84. Tissue distribution analysis in mRNA level showed that it was highly expressed in gills, hemocytes, and intestine, and lowly expressed in hearts, hepatopancreas, and stomach. Time course expression pattern analysis showed that PcLysM was upregulated in hemocytes and gills after challenge with Vibrio anguillarum, and it was upregulated at 12h after challenge with Staphylococcus aureus in gills. The recombinant PcLysM could bind to different bacteria, and yeast. Further study revealed that PcLysM could bind to peptidoglycans from different bacteria, and chitin. After PcLysM was knocked down, the upregulation of antimicrobial peptide (AMP) genes (crustins and antilipopolysaccharide factors) was suppressed in response to bacterial infection in gills. These results suggest that PcLysM recognizes different microorganisms through binding to polysaccharides, such as peptidoglycans and chitin and regulates the expression of some antimicrobial peptide genes though unknown pathways and regulates the expression of some antimicrobial peptide genes though unknown pathways. This study might provide a clue to elucidate the roles of PcLysM in the innate immune reaction of crayfish P. clarkii.
authors.affiliation: The Key Laboratory of Plant Cell Engineering and Germplasm Innovation of Ministry of Education, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China.
authors.forename: Xiu-Zhen
authors.initials: XZ
authors.lastname: Shi
authors.forename: Jing
authors.initials: J
authors.lastname: Zhou
authors.forename: Jiang-Feng
authors.initials: JF
authors.lastname: Lan
authors.forename: Yu-Ping
authors.initials: YP
authors.lastname: Jia
authors.forename: Xiao-Fan
authors.initials: XF
authors.lastname: Zhao
authors.forename: Jin-Xing
authors.initials: JX
authors.lastname: Wang
mesh_terms: D020816:Amino Acid Motifs; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000235:genetics / Q000378:metabolism; D060829:Arthropod Proteins / Q000737:chemistry / Q000502:physiology*; D003400:Astacoidea / Q000276:immunology* / Q000382:microbiology; D001412:Bacillus subtilis / Q000276:immunology; D001426:Bacterial Proteins / Q000276:immunology; D002686:Chitin / Q000276:immunology; D015870:Gene Expression; D005880:Gills / Q000276:immunology / Q000378:metabolism / Q000382:microbiology; D006434:Hemocytes / Q000276:immunology / Q000378:metabolism / Q000382:microbiology; D054884:Host-Pathogen Interactions; D009928:Organ Specificity; D010802:Phylogeny; D011485:Protein Binding; D011509:Proteoglycans / Q000276:immunology; D017422:Sequence Analysis, DNA; D013211:Staphylococcus aureus / Q000276:immunology; D015854:Up-Regulation / Q000276:immunology; D014733:Vibrio / Q000276:immunology
chemical_list: D023181:Antimicrobial Cationic Peptides; D060829:Arthropod Proteins; D001426:Bacterial Proteins; D011509:Proteoglycans; D002686:Chitin