Tributyltin chloride-induced effects on protein tyrosine phosphorylation and on extracellular-signal-regulated kinase (ERK) phosphorilation in Ascidian Phallusia mammilata

Ascidians represent an intriguing candidate experimental system for studying the effects of environmental stress. We studied TBT effects and probable related pathways were investigated on ascidian embryos by using Western immunoblotting. Among the various signal transduction pathways involved in response to environmental stress, both tyrosine kinase signalling and MAPKs have been played a significant role. To better understand molecular mechanisms after exposure to TBT we studied the two signal transduction pathways above mentioned. Attempting to unravel the molecular effects of TBT-induced on ascidians embryogenesis, TBT treatments carried out in Phallusia mammillata embryos at gastrula stage. We found different levels of tyrosine protein phosphorylation in response to the incubation with TBT in µM range and a remarkable ERK phosphorylation inhibition dose-dependent with 10, 50 and 100 µM of TBT solution. Based on these data, the use of tyrosine phosphorylation leves and MAPK signal transduction could be considered as biomarkers in the response of marine organisms to pollutant.