title: A cnidarian homologue of translationally controlled tumor protein (P23/TCTP).
abstract: A protein homologous to P23, or translationally controlled tumor protein (TCTP), was cloned in Hydra vulgaris, the most ancient type of metazoan from which P23/TCTP has been characterized to date. Hydra P23/TCTP is composed of 184 amino acids and is encoded by a single mRNA of 700 bp. This invertebrate P23/TCTP is well conserved compared to those of other invertebrate and vertebrate species. Expression of Hydra P23/TCTP was confirmed by western blot of Hydra cell lysates using a polyclonal antibody against murine recombinant P23/TCTP. Spatial distribution of P23/TCTP mRNA and protein in Hydra was studied using in situ hybridization and immunostaining, respectively. Hydra P23/TCTP expression along the longitudinal body axis is regulated at both the transcriptional and the translational level. High levels of P23/TCTP mRNA were detected in a subpopulation of cells in the body column. In contrast, no mRNA was evident in the differentiated cells of the head and the foot regions. Coincidentally, P23/TCTP protein also concentrates to the body column, with no detectable protein in the head and foot region. However, despite the existence of P23/TCTP mRNA in both the ectoderm and endoderm in the body column, its protein is localized to the endodermal cells, suggesting a regulatory mechanism at the translational level. Taken together, the expression pattern of P23/TCTP in Hydra correlates with regions in which cell proliferation is actively occurring and its expression is excluded from regions where terminal differentiation has occurred.
authors.affiliation: Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, KS 66160-7400, USA.
authors.forename: L
authors.initials: L
authors.lastname: Yan
authors.forename: K
authors.initials: K
authors.lastname: Fei
authors.forename: D
authors.initials: D
authors.lastname: Bridge
authors.forename: M P
authors.initials: MP
authors.lastname: Sarras
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D014408:Biomarkers, Tumor; D002135:Calcium-Binding Proteins / Q000737:chemistry / Q000235:genetics*; D003001:Cloning, Molecular; D018076:DNA, Complementary; D006801:Humans; D006829:Hydra / Q000235:genetics*; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D000090324:Tumor Protein, Translationally-Controlled 1
chemical_list: D014408:Biomarkers, Tumor; D002135:Calcium-Binding Proteins; D018076:DNA, Complementary; C000715647:TPT1 protein, human; D000090324:Tumor Protein, Translationally-Controlled 1