title: Molecular cloning and expression analysis of alpha 2-macroglobulin in the kuruma shrimp, Marsupenaeus japonicus.
abstract: The cDNA encoding the kuruma shrimp, Marsupenaeus japonicus alpha(2)-macroglobulin (alpha(2)M) was obtained by screening a haemocyte cDNA library and 5' RACE PCR amplification. The full length cDNA of 4748 bp contains an open reading frame of 4518 nucleotides that translates into a 1505-amino acid putative peptide, with a 5'untranslated region (UTR) of 59 bp and a 3'UTR of 171 bp. The open reading frame encodes an N-terminal signal sequence of 17 residues and a mature protein of 1488 residues. The entire amino acid sequence is similar to the alpha(2)M sequences of arthropods (30-31% identity), mammals (26-27% identity) and fish (25-28% identity). The M. japonicus alpha(2)M sequence contains putative functional domains including a bait region, an internal thiol ester site, and a receptor-binding domain, which are present in mammalian alpha(2)Ms. In a healthy shrimp, the mRNA of alpha(2)M was mainly expressed in haemocytes. In addition, the expression level of alpha(2)M mRNA was dramatically increased by through time upon oral administration of peptidoglycan (PG), which is an immune stimulant. The highest expression of alpha(2)M mRNA was observed 7 days after feeding with PG. These results suggest that the shrimp alpha(2)M is an important molecule in immune system.
authors.affiliation: Laboratory of Genome Science, Graduate School of Marine Science and Technology, Tokyo University of Marine Science and Technology, Konan 4-5-7, Minato, Tokyo, Japan.
authors.forename: Achara
authors.initials: A
authors.lastname: Rattanachai
authors.forename: Ikuo
authors.initials: I
authors.lastname: Hirono
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Ohira
authors.forename: Yukinori
authors.initials: Y
authors.lastname: Takahashi
authors.forename: Takashi
authors.initials: T
authors.lastname: Aoki
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D017931:DNA Primers; D018076:DNA, Complementary / Q000235:genetics; D005786:Gene Expression Regulation / Q000187:drug effects*; D006434:Hemocytes / Q000378:metabolism; D008969:Molecular Sequence Data; D016366:Open Reading Frames / Q000235:genetics; D033561:Penaeidae / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D010457:Peptidoglycan / Q000494:pharmacology*; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000235:genetics*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D000511:alpha-Macroglobulins / Q000235:genetics* / Q000378:metabolism
chemical_list: D017931:DNA Primers; D018076:DNA, Complementary; D010457:Peptidoglycan; D012333:RNA, Messenger; D000511:alpha-Macroglobulins