RESUMO
The cDNA sequence of foot-specific peroxidase PPOD1 from the Chinese strain of Hydra magnipapillata was cloned by reverse transcription-polymerase chain reaction. The cDNA sequence contained a coding region with an 873-bp open reading frame, a 31-bp 5'-untranslated region, and a 36-bp 3'-untranslated region. The structure prediction results showed that PPOD1 contains 10.34% of α-helix, 38.62% of extended strand, 12.41% of ß-turn, and 38.62% of random coil. The structural core was α-helix at the N terminus. The GenBank protein blast server showed that PPOD1 contains 2 fascin-like domains. In addition, high-level PPOD1 activity was only present in the ectodermal epithelial cells located on the edge of the adhesive face of the basal disc, and that these cells extended lamellipodia and filopodia when the basal disc was tightly attached to a glass slide. The fascin-like domains of Hydra PPOD1 might contribute to the bundling of the actin filament of these cells, and hence, the formation of filopodia. In conclusion, these cells might play an important role in strengthening the adsorbability of the basal disc to substrates.
Assuntos
Regulação Enzimológica da Expressão Gênica , Hydra/genética , Fases de Leitura Aberta/genética , Peroxidase/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Sítios de Ligação/genética , China , Clonagem Molecular , DNA Complementar/química , DNA Complementar/genética , Hydra/enzimologia , Modelos Moleculares , Dados de Sequência Molecular , Peroxidase/classificação , Peroxidase/metabolismo , Filogenia , Células Procarióticas/metabolismo , Estrutura Terciária de Proteína , Pseudópodes/enzimologia , Pseudópodes/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA , Homologia de Sequência de AminoácidosRESUMO
Different signaling systems coordinate and regulate the development of a multicellular organism. In hydra, the canonical Wnt pathway and the signal transduction pathways mediated by PKC and Src regulate early stages of head formation. In this paper, we present evidence for the participation of a third pathway, the PI3K-PKB pathway, involved in this process. The data presented here are consistent with the participation of ERK 1-2 as a point of convergence for the transduction pathways mediated by PKC, Src and PI3K for the regulation of the regeneration of the head in hydra. The specific developmental point regulated by them appears to be the commitment of tissue at the apical end of the regenerate to form the head organizer.
Assuntos
Hydra/enzimologia , Proteína Quinase 1 Ativada por Mitógeno/fisiologia , Proteína Quinase 3 Ativada por Mitógeno/fisiologia , Fosfatidilinositol 3-Quinases/fisiologia , Regeneração/fisiologia , Animais , Regulação da Expressão Gênica no Desenvolvimento , Cabeça/fisiologia , Hydra/fisiologia , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Fosforilação , Receptores Proteína Tirosina Quinases/fisiologia , Transdução de Sinais/fisiologiaRESUMO
In Hydra, head regeneration and bud formation appear to be very similar processes. The fact that there are genes whose expression is specific for one of the two processes suggests that they do not have identical molecular bases. We analyzed the signal transduction pathways regulating bud development using inhibitors of protein kinase C, Src, PI3K and ERK. The four inhibitors reversibly blocked bud formation in Hydra when applied before stage 1. Once the bud reached stage 3, three of them had no effect and the bud developed normally. The inhibitors blocked the expression of Budhead, an early head marker, and of CnOtx which are specific for bud formation. The results are in agreement with the central role of a signaling pathway mediated by Src on bud development.