کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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2433629 | 1106842 | 2007 | 11 صفحه PDF | دانلود رایگان |
Myxovirus resistance (Mx) protein is one of the most studied antiviral proteins. It is induced by the type I interferon system (IFN α/β) in various vertebrates, but its expression has not been identified or characterized in mollusks or other multi-cellular invertebrates to date. In this study, we isolated the Mx gene from a disk abalone (Haliotis discus discus) normalized cDNA library. Mx cDNA was sequenced, cloned and compared to other known Mx proteins. The full-length 1664 bp of abalone Mx cDNA contained a 1533-bp open reading frame that codes for 511 amino acids. Within the coding sequence of abalone Mx, characteristic features were found, such as a tripartite guanosine-5′-triphosphate (GTP)-binding motif and a dynamin family signature. In addition, leucine residues in the C-terminal region displayed a special leucine domain at L468, L475, L489 and L510, suggesting that abalone Mx may have a similar oligomerization function as other leucine zipper motifs. Abalone Mx protein exhibited 44% amino acid similarity with channel catfish Mx1, rainbow trout Mx2 and Atlantic halibut Mx. Abalones were injected intramuscularly with the known IFN inducer poly I:C and RT-PCR was performed for Mx mRNA analysis. The results showed enhanced Mx expression in abalone gill and digestive tissues 24 h as well as 48 h after injection of poly I:C. Mx mRNA was expressed in gill, digestive gland, mantle and foot tissues in healthy abalone, suggesting that the basal level of Mx expressed is tissue-specific. There is no known Mx protein closely related to abalone Mx according to phylogenetic analysis. Abalone Mx may have diverged from a common gene ancestor of fish and mammalian Mx proteins, since abalone Mx showed high similarity in terms of conserved tripartite GTP-binding, dynamin family signature motifs and poly I:C enhancement of Mx mRNA expression.
Journal: Fish & Shellfish Immunology - Volume 23, Issue 1, July 2007, Pages 86–96