title: Identification and characterization of a QM protein as a possible peptidoglycan recognition protein (PGRP) from the giant tiger shrimp Penaeus monodon.
abstract: In an attempt to identify a peptidoglycan recognition protein (PGRP) in Penaeus (Penaeus) monodon, in vitro pull-down binding assays were used between shrimp proteins and purified peptidoglycan (PG). By gel electrophoresis and mass spectrometry followed by Mascot program analysis, proteins from shrimp hemocyte peripheral membrane proteins showed significant homology to records for a QM protein, actin and prophenoloxidase 2 precursor (proPO2), while proteins from cell-free plasma showed significant homology to records for a vitellogenin, a fibrinogen related protein (FREP) and a C-type lectin. Due to time and resource limitations, specific binding to PG was examined only for recombinant PmQM protein and PmLec that were synthesized based on sequences reported in the Genbank database (accession numbers FJ766846 and DQ078266, respectively). An in vitro assay revealed that hemocytes would bind with and encapsulate agarose beads coated with recombinant PmQM (rPmQM) or rPmLec and that melanization followed 2h post-encapsulation. ELISA tests confirmed specific binding of rPmQM protein to PG. This is the first time that PmQM has been reported as a potential PGRP in shrimp or any other crustacean. The two other potential PGRP identified (FREP and the vitellin-like protein present in male P. monodon, unlike other vitellin subunits) should also be expressed heterologously and tested for their ability to activate shrimp hemocytes.
authors.affiliation: Department of Biotechnology, Faculty of Science, Mahidol University, Rama VI Rd., Bangkok 10400, Thailand; Center of Excellence for Shrimp Molecular Biology and Biotechnology, Faculty of Science, Mahidol University, Rama VI Rd., Bangkok 10400, Thailand.
authors.forename: Attasit
authors.initials: A
authors.lastname: Udompetcharaporn
authors.affiliation: Department of Comparative Physiology, Evolutionary Biology Center (EBC), Uppsala University, Norbyvägen 18A, Uppsala, Sweden.
authors.forename: Kingkamon
authors.initials: K
authors.lastname: Junkunlo
authors.affiliation: Department of Biotechnology, Faculty of Science, Mahidol University, Rama VI Rd., Bangkok 10400, Thailand; Center of Excellence for Shrimp Molecular Biology and Biotechnology, Faculty of Science, Mahidol University, Rama VI Rd., Bangkok 10400, Thailand; National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathumthani 12120, Thailand.
authors.forename: Saengchan
authors.initials: S
authors.lastname: Senapin
authors.affiliation: Proteomics Research Laboratory, Genome Institute, National Center for Genetic Engineering and Biotechnology (BIOTEC), Thailand Science Park, Pathumthani 12120, Thailand.
authors.forename: Sittiruk
authors.initials: S
authors.lastname: Roytrakul
authors.affiliation: Department of Biotechnology, Faculty of Science, Mahidol University, Rama VI Rd., Bangkok 10400, Thailand; Center of Excellence for Shrimp Molecular Biology and Biotechnology, Faculty of Science, Mahidol University, Rama VI Rd., Bangkok 10400, Thailand; National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathumthani 12120, Thailand.
authors.forename: Timothy W
authors.initials: TW
authors.lastname: Flegel
authors.affiliation: Department of Biotechnology, Faculty of Science, Mahidol University, Rama VI Rd., Bangkok 10400, Thailand; Center of Excellence for Shrimp Molecular Biology and Biotechnology, Faculty of Science, Mahidol University, Rama VI Rd., Bangkok 10400, Thailand; Shrimp-Virus Interaction Laboratory (ASVI), National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Rama VI Rd., Bangkok 10400, Thailand. Electronic address: kallaya@biotec.or.th.
authors.forename: Kallaya
authors.initials: K
authors.lastname: Sritunyalucksana
mesh_terms: D000818:Animals; D060829:Arthropod Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D006434:Hemocytes / Q000276:immunology / Q000378:metabolism; D007113:Immunity, Innate; D008297:Male; D008543:Melanins / Q000096:biosynthesis; D033561:Penaeidae / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D010457:Peptidoglycan / Q000737:chemistry; D011485:Protein Binding; D017386:Sequence Homology, Amino Acid
chemical_list: D060829:Arthropod Proteins; D002352:Carrier Proteins; D008543:Melanins; D010457:Peptidoglycan; C118897:peptidoglycan recognition protein
keywords: C-type lectin; Penaeus monodon; Peptidoglycan recognition proteins; PmLec; PmQM; QM protein