Determination of the protein expression profiles of Propsilocerus akamusi (Tokunaga) Malpighian tubules response to cadmium stress by iTRAQ coupled LC-MS/MS.

Propsilocerus akamusi (Tokunaga) is an important prey species for fish and aquatic birds, which represent an important link in the aquatic food chain as other species of Chironomidae. Malpighian tubules (MT) play an important role in metabolism and detoxification of harmful compounds and metal accumulation. Our previous studies have reported that P. akamusi have an extraordinary resistance to Cd. In this paper, iTRAQ-based proteomics technology was first used to study the differential proteomics of MT of Propsilocerus akamusi under sublethal Cd stress for different time courses. 118 differential expressed proteins (DEPs) were identified through LC–MS/MS and further classified into 26 GO functional groups. Our results showed that metabolic process was the main biological functional categories. Cluster of orthologous groups of proteins (COG) analysis was also performed based on the number of unique proteins identified in each functional category, 21 metabolism-related DEPs were identified. P. akamusi adapted to Cd stress mainly by inducing the processes of lipid metabolism of MT and lipid may play a possible protection role in cadmium resistance in MT. The results provide important information for research on molecular mechanisms of Cd-stress adaption in Malpighian tubules of P. akamusi.