GRP78 from grass carp (Ctenopharyngodon idella) provides cytoplasm protection against thermal and Pb2+ stress

► CiGRP78 is up-regulated upon thermal, cold or Pb2+ stress in almost tissues. ► CiGRP78 displays higher expression level in liver. ► CiGRP78 contributes to protecting cell against thermal or cold extremes. ► CiGRP78 provides a transient cytoplasm protection against Pb2+ stress.