High expression of a novel leucine-rich repeat protein in hemocytes and the lymphoid organ of the black tiger shrimp Penaeus monodon.
A novel leucine-rich repeat (LRR) cDNA has been cloned from hemocytes of the black tiger shrimp Penaeus monodon by 5' rapid amplification of cDNA ends. The full-length of P. monodon LRR (PmLRR) consisted of 2604 bp with a 1686-bp open reading frame, encoding 561 amino acids. The deduced protein contained a high proportion of leucine residues (17%) and had significant homology to LRR-containing proteins from bacteria to humans. Sixteen tandem LRR motifs of 23-24 amino acids in length occurred in the primary sequence. The computed 3D structure revealed a horseshoe shape consisting of alternately repeated strand and helical domains. Such structures are generally considered to mediate protein - protein interactions and to our knowledge, this is the first report of an LRR protein from a crustacean. PmLRR expression was tissue-specific (i.e. highest in hemocytes, intestine and lymphoid organ) suggesting that it may play some roles in shrimp defense against pathogens. A preliminary test suggested that PmLRR may be down-regulated after viral injection.
Sriphaijit
Thanawat
T
Department of Biotechnology, Faculty of Science, Mahidol University, Rama VI Road, Bangkok 10400, Thailand.
Senapin
Saengchan
S
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017931:DNA Primers / Q000737:chemistry; D018076:DNA, Complementary / Q000737:chemistry; D015870:Gene Expression / Q000276:immunology*; D006434:Hemocytes / Q000276:immunology; D000090263:Leucine-Rich Repeat Proteins; D008221:Lymphoid Tissue / Q000276:immunology; D008969:Molecular Sequence Data; D033561:Penaeidae / Q000502:physiology*; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D046828:Roniviridae / Q000276:immunology; D016415:Sequence Alignment / Q000662:veterinary; D013047:Specific Pathogen-Free Organisms; D013997:Time Factors; D046848:White spot syndrome virus 1 / Q000276:immunology
D017931:DNA Primers; D018076:DNA, Complementary; D000090263:Leucine-Rich Repeat Proteins; D011506:Proteins