| Title: | "Identification and characterization of class B scavenger receptor CD36 from the hard tick, Haemaphysalis longicornis" |
| Author(s): | Aung KM; Boldbaatar D; Liao M; Umemiya-Shirafuji R; Nakao S; Matsuoka T; Tanaka T; Fujisaki K; |
| Address: | "Department of Pathological and Preventive Veterinary Science, The United Graduate School of Veterinary Science, Yamaguchi University, 1677-1 Yoshida, Yamaguchi, 753-8515, Japan" |
| DOI: | 10.1007/s00436-010-2053-1 |
| ISSN/ISBN: | 1432-1955 (Electronic) 0932-0113 (Linking) |
| Abstract: | "Scavenger receptors (SRs) are cell-surface proteins and exhibit distinctive ligand-binding properties, recognizing a wide range of ligands that include microbial surface constituents and intact microbes. The class B scavenger receptor CD36 (SRB) is predominantly expressed by macrophages and is considered important in innate immunity. We here show the identification and characterization of SRB from the hard ixodid tick, Haemaphysalis longicornis (HlSRB). The full-length cDNA was 2,908 bp, including an ORF encoding of 1,518 amino acids with a pI value of 5.83. H. longicornis SRB contains a hydrophobic SRB domain and four centrally clustered cysteine residues for arrangement of disulfide bridges. Deduced amino acid sequence has an identity of 30-38% with the SRB of other organisms. RT-PCR analysis showed that mRNA transcripts were expressed in multiple organs of adult ticks but with a different transcript level in the developmental stages of H. longicornis ticks. His-tagged recombinant HlSRB was expressed in Escherichia coli with an expected molecular mass of 50 kDa. In Western blot analysis, mouse anti-rHlSRB serum recognized a strong reaction with a 50 kDa protein band in lysates prepared from egg and adult tick but showed a weak reaction with lysates of larva and nymph. In an indirect immunofluorescent antibody test, HlSRB antiserum recognized the protein located on the midgut, salivary glands, and ovary of partially fed H. longicornis females. Silencing of the HlSRB gene by RNAi led to a significant reduction in the engorged female body weight. It is noteworthy that more than a dozen SRB orthologs have been identified in the genomes of insect species with functions related to pheromone signaling, innate immunity, phagocytic clearance of apoptotic cells, and various aspects of the fatty acid metabolism. This is the first report of the identification and characterization of the SRB homologue in Chelicerata, including ticks, horseshoe crabs, scorpions, spiders, and mites" |
| Keywords: | "Amino Acid Sequence Animals Base Sequence CD36 Antigens/chemistry/*genetics/*metabolism DNA, Complementary/genetics Female Gene Library Gene Silencing Insect Proteins/chemistry/*genetics/*metabolism Ixodidae/genetics/*metabolism Molecular Sequence Data Ph;" |
| Notes: | "MedlineAung, Kyaw Min Boldbaatar, Damdinsuren Liao, Min Umemiya-Shirafuji, Rika Nakao, Sumihiro Matsuoka, Terushige Tanaka, Tetsuya Fujisaki, Kozo eng Research Support, Non-U.S. Gov't Germany 2010/09/28 Parasitol Res. 2011 Feb; 108(2):273-85. doi: 10.1007/s00436-010-2053-1. Epub 2010 Sep 25" |
