Peptide-based Tools for Investigating Protein Tyrosine Phosphatases Involved in Parkinsons Disease

Project: Research

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Tyrosine phosphorylation is closely involved in regulating numerous vital cellularprocesses such as transcriptional activation, cell proliferation and cell differentiation. Thelevel of intracellular tyrosine phosphorylation is stringently controlled by protein tyrosinephosphatases (PTPs) and protein tyrosine kinases. Biological studies have shown thatPTPs play crucial roles in regulating various important cellular functions. Dysfunction ofPTPs, on the other hand, could lead to the pathogenesis of a variety of diseases. Till date,many PTPs have been identified as potential therapeutic targets.Current researches on PTPs are generally focused on investigating PTPs related tocancers. Studies on PTPs related to neurological diseases, however, are rather rare. In thisproposal, we will use the peptide microarray approach to decipher the substratespecificity of PTPs involved in Parkinson’s disease (PD). In our study, a phosphopeptidelibrary, whose sequence is derived from putative phosphorylated protein substrates, willbe synthesized and anchored onto microarray. The fabricated phosphopeptide array willthen be used to profile the substrate specificities of target PTPs. Through the proposedresearch, we hope to gain a better understanding of the substrate recognition andspecificity of the PTPs related to PD. The information obtained from microarrayexperiment will provide valuable insight into PTP’s biological functions in PD and propelfuture design of PTP inhibitors. Furthermore, the results of microarray screening will alsoprovide key information to design selective fluorescent probes for targeting specific PTP.We will apply the fluorescent probes to monitor specific PTP activities in living cells.Parkinson’s disease is commonly known to involve the aggregation ofa-synuclein toform toxic fibrils. Recent studies have shown that tyrosine 125 phosphorylation ofa-synuclein can inhibit the toxic oligomer formation and thus reduce neuron toxicity.However, the specific PTP responsible for dephosphorylation ofa-synuclein is stillunknown. In the third part of this study, we will construct protein-based probes tocovalently trap the endogenous PTPs during the dephosphorylation process. Specificallywe will use expressed protein ligation approach to generatea-synuclein which containsan unnatural pY analogue. The obtained protein-based probe will be capable ofspecifically trapping the PTPs during dephosphorylation. The identified PTP will shednew light on the roles of PTPs in Parkinson’s disease.The current research team has extensive experience in peptide microarray, proteomics,molecular biology and neuroscience. We believe that the proposed study will contributeimmensely to the advancement of PTP field and PD research.?


Project number9042230
Grant typeGRF
Effective start/end date1/01/1619/12/19

    Research areas

  • peptide microarray,substrate specificity,high-throughput screening,protein tyrosine phosphatase,