engleski

SILAC-MS analysis of human dipeptidyl peptidase 3 interactome

Dipeptidyl peptidase 3 (DPP3) is the zinc metallopeptidase, which cleaves dipeptides from the amino-termini of 3 to 10 amino acids long peptides. Its peptidase activity and ubiquitous presence indicate that it might have a role in the final stages of protein turnover in the cells, however, the precise physiological roles of this peptidase have not been proven yet. Human DPP3 (hDPP3) has additional proposed roles in the regulation of blood pressure and pain, based on its affinity and activity towards several bioactive peptides, whereas the results of several recent studies indicate its role in the regulation of oxidative stress response. The role of hDPP3 in the oxidative stress response is mediated through its interaction with Keap1 protein. Keap1 acts as the substrate adaptor for E3 ubiquitin ligase that binds the transcription factor Nrf2 in the cytoplasm, thus facilitating its ubiquitination and subsequent degradation in the basal conditions. Under oxidative stress conditions, Keap1 releases Nrf2 from the complex, enabling its translocation to the nucleus and the transcription of the whole array of genes coding for proteins involved in the oxidative stress response. One of the mechanisms that facilitates release of Nrf2 from the Keap1 complex is binding of hDPP3 to Keap1. In order to further study the physiological role of DPP3, we investigated hDPP3 interactome by SILAC-MS high-throughput approach. We identified around 30 putative interactors of hDPP3 that were detected in at least 2 out of 4 biological replicates. Ten proteins were chosen as the most promising candidates, based on the scores in the SILAC-MS and gene ontology analysis showing their involvement in the same cellular processes. Chosen putative interactors are going to be investigated further by various biochemical and molecular biology methods in order to determine the physiological significance of their interaction with hDPP3.

human didpeptydil peptidase 3 ; protein-protein interactions

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