Life Sciences & Biotechnology
Title : | A proteome centric view of Praja1 ubiquitin ligase in proteostasis decline and disease manifestation |
Area of research : | Life Sciences & Biotechnology |
Focus area : | Proteomics, Disease Mechanisms |
Principal Investigator : | Dr. Atin Kumar Mandal, Bose Institute, Kolkata, West Bengal |
Timeline Start Year : | 2024 |
Timeline End Year : | 2027 |
Contact info : | mandalak@jcbose.ac.in |
Details
Executive Summary : | Ubiquitin ligases (E3 ligases) maintain proteome balance by tagging proteins, both normal and misfolded conformations with ubiquitin for clearance by the proteasomal machinery or autophagy. Increasing evidence has highlighted the relevance of aberrant function or regulation of E3 ligases at the roots of developmental disorders, cancer, and neurodegeneration. We reported earlier that Praja1 (PJA1), a RING finger ubiquitin ligase promotes ubiquitination and degradation of polyQ proteins like Ataxin-3 and Huntingtin and reduces polyQ-associated pathogenesis. Apart from polyQ proteins, PJA1 also controls the turnover of a striking number of aggregation-prone proteins such as TDP43, α-Synuclein, SOD1, and FUS. Interestingly, it has been seen that PJA1 is highly enriched in brain tissue with the most being in neuronal cells. Altogether, PJA1 acts as a mitigator of proteotoxic stress and serves as a crucial E3 ligase of the brain proteome. Hence, it is probable that dysfunction of this robust E3 ligase might result in pathogenesis and onset of neurodegeneration. Therefore, we speculate that PJA1 ligase maintains a crucial proteostasis network in brain proteome, the identification of which not only will shed light on its substrates but will also lead to strategies for therapeutic interventions for such debilitating diseases. Notably, PJA1 is significantly upregulated in glioblastomas and gastrointestinal cancer and has been implicated in osteoblast differentiation and myogenesis. Therefore, analysis of its interaction network will also reveal cellular functions mediated by PJA1 in the context of malignancy. In this project, we will study- • The interactome of PJA1 and its role in maintaining cellular protein homeostasis • Identify the mechanism of molecular linkages that act in concert with PJA1 • Its mode of action, mechanism of substrate recognition, and regulation of activity through post-translational modifications We will identify PJA1 interactors through shotgun proteomics approach and validate the procured data by western blotting, co-immunoprecipitation, and microscopic assays. We will characterize the interaction network of PJA1 in primary cell line and discern the cell-specific remodeling of PJA1 interactome. Immunohistochemistry studies on disease-induced mice models and in-vitro ubiquitination assay of PJA1 will also be done. We presume that PJA1 is a self-regulated ligase and downregulation of its activity might have a profound role in stemming proteomic instability and disease presentation. Thus, deciphering the regulation of PJA1 ligase activity in normal and diseased conditions will reveal novel therapeutic modalities through modifications of its activity. The overall work will give us a comprehensive understanding of the surveillance network of PJA1 and might provide avenues for drug discovery based on targeted protein degradation and proteolysis-targeting chimera (PROTAC) technology. |
Total Budget (INR): | 59,20,992 |
Organizations involved