Proline biosynthesis genes and their regulation under salinity stress in the euryhaline copepod Tigriopus californicus.

摘要: Abstract Diverse organisms regulate concentrations of intracellular organic osmolytes in response to changes environmental salinity or desiccation. In marine crustaceans, accumulation high proline is a dominant component hyperosmotic stress. the euryhaline copepod Tigriopus californicus, synthesis from its metabolic precursor glutamate tightly regulated by salinity. Here, for first time invertebrate, genes responsible this pathway have been cloned and characterized. The two proteins display sequence features homologous enzymes identified other eukaryotes. One genes, δ1-pyrroline-5-carboxylase reductase (P5CR), demonstrated enzyme activity when expressed proline-auxotroph bacteria, while second, synthase (P5CS), does not rescue bacteria. contrast results higher plants, neither levels P5CS nor P5CR mRNAs increase stress T. californicus. Hence, regulation during osmotic californicus likely mediated some form post-transcriptional either P5CR. Understanding may elucidate mechanisms limiting ranges taxa.