Genomic organization of the translationally controlled tumor protein (TCTP) gene from shrimp Marsupenaeus japonicus

Characterization of Translationally Controlled Tumour Protein from the Sea Anemone Anemonia viridis and Transcriptome Wide Identification of Cnidarian Homologues

Gene family encoding translationally controlled tumour protein (TCTP) is defined as highly conserved among organisms; however, there is limited knowledge of non-bilateria. In this study, the first TCTP homologue from anthozoan was characterised in the Mediterranean Sea anemone, Anemonia viridis. The release of the genome sequence of Acropora digitifera, Exaiptasia pallida, Nematostella vectensis and Hydra vulgaris enabled a comprehensive study of the molecular evolution of TCTP family among cnidarians. A comparison among TCTP members from Cnidaria and Bilateria showed conserved intron exon organization, evolutionary conserved TCTP signatures and 3D protein structure. The pattern of mRNA expression profile was also defined in A. viridis. These analyses revealed a constitutive mRNA expression especially in tissues with active proliferation. Additionally, the transcriptional profile of A. viridis TCTP (AvTCTP) after challenges with different abiotic/biotic stresses showed induction by extreme temperatures, heavy metals exposure and immune stimulation. These results suggest the involvement of AvTCTP in the sea anemone defensome taking part in environmental stress and immune responses.

The immunomodulation of a maternal translationally controlled tumor protein (TCTP) in Zhikong scallop Chlamys farreri

Translationally controlled tumor protein (TCTP) is initially described as a highly conserved protein implicated in cell growth, and it is subsequently confirmed to play important roles in mediating the innate immune response, especially the inflammatory. In the present study, the full-length cDNA sequence of a TCTP from Zhikong scallop Chlamys farreri (designed as CfTCTP) was cloned by rapid amplification of cDNA ends (RACE) technique based on the expression sequence tag (EST) analysis. It was of 1230 bp with an open reading frame (ORF) of 543 bp encoding a polypeptide of 180 amino acids. The deduced amino acid sequence contained a conserved TCTP signature sequence (from I⁴⁷ to E⁵⁸) and it shared 26.1%-48.9% similarities with previously identified TCTPs. CfTCTP was clustered with the TCTP from Argopectehs irradias in the phylogenetic tree and was designated into a single branch of mollusk with TCTP from Ruditapes philippinarum. The mRNA transcripts of CfTCTP were constitutively expressed in all the tested tissues, including haemocytes, muscle, mantle, gill, hepatopancreas, kidney and gonad, with the highest expression level in hepatopancreas. The mRNA expression level of CfTCTP in oocytes and fertilized eggs kept at a higher level, and was down-regulated from 2-cell embryos to the lowest level in gastrula. Then it was up-regulated in trochophore and dropped down in the late veliger larvae to the similar level as that in oocytes. After pathogen-associated molecular patterns (PAMPs) stimulation, the expression of CfTCTP mRNA in haemocytes was increased at 3 or 6 h, and fall down to the normal level at 24 h. The recombinant protein of CfTCTP could induce the release of histamine from BT-549 cells. All these results indicated that CfTCTP was a pro-inflammatory factor and it could be maternally transferred from female gonad to oocytes and offspring, and play pivotal role in the embryonic development and immune protection of scallops.