RESUMO
Phospholipid scramblases (PLSCRs) are the conserved calcium-binding, type II transmembrane proteins synthesized in all eukaryotic organisms. In mammals, these proteins play essential roles in various physiological processes, especially in the immune responses. However, the existence of PLSCRs and their biological functions in planarian are still unknown at present. In this study, a new member of PLSCRs was identified in planarian Dugesia japonica (D. japonica), named DjPLSCR. The sequence analysis revealed that it contains an opening reading frame consisting of 726bp encoding a putative protein of 241 amino acids with a predicted molecular mass of ~28.7kDa and an isoelectric point of 6.21. Whole-mount in situ hybridization showed that mRNAs of DjPLSCR are predominantly expressed in adult and regenerative pharynx which is an important organ of immune system in planarians. Importantly, we found that the transcription level of DjPLSCR was significantly upregulated when planarians were stimulated with the pathogen-associated molecular patterns [polyinosinic-polycytidylic acid, lipopolysaccharide, peptidoglycan and ß-glucan], suggesting that DjPLSCR is involved in the immune response upon pathogen invasion. Our findings provide the first experimental insights into the characteristics and potential functions of PLSCR in planarians.
Assuntos
Proteínas de Helminto/genética , Proteínas de Helminto/metabolismo , Proteínas de Transferência de Fosfolipídeos/genética , Proteínas de Transferência de Fosfolipídeos/metabolismo , Planárias/enzimologia , Planárias/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Sequência Conservada , DNA Complementar/genética , Regulação Enzimológica da Expressão Gênica , Genes de Helmintos , Proteínas de Helminto/química , Proteínas de Transferência de Fosfolipídeos/química , Filogenia , Planárias/fisiologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Regeneração/genética , Homologia de Sequência de Aminoácidos , Distribuição TecidualRESUMO
Prophenoloxidase (tyrosinase) widely distributed in invertebrates and vertebrates, and plays a crucial role in the innate immune. In the present study, the full-length cDNA of a tyrosinase-like (designated AmphiTYR) was cloned from amphioxus Branchiostoma japonicum by PCR techniques. The full-length cDNA of AmphiTYR is 2314 bp, and its predicted open-reading frame codes for a protein of 544 amino acids with a predicted molecular mass of approximately 60.9 kDa and an isoelectric point of 5.65. It has a conserved putative copper-binding domain with six histidines in tyrosinase proteins. Six potential N-linked glycosylation sites and 14 conserved cysteine residues were also predicted to be present in B. japonicum tyrosinase. Homology analysis revealed that AmphiTYR was higher similar to vertebrates tyrosinases (32.5-40.5%) than to invertebrates phenoloxidase (6.4-25.4%). In the adult, AmphiTYR mRNA was expressed in the muscle, epidermis, notochord, ovary, hepatic caecum, pharynx and gill, but not in the neural tube, intestines and testis. During the different development stages from unfertilized egg to larvae of amphioxus, AmphiTYR expressed during all the amphioxus development. These results indicated that AmphiTYR gene not only play a pivotal role in innate immune but also play an important role during embryonic development of cephalochordate amphioxus.