iProXProteomicsChunkit KwokHomo Sapienshttp://www.iprox.org/page/project.html?id=IPX0010270000ckkwok42@cityu.edu.hkCity University of Hong KongiProXRNA G-quadruplexes (rG4s) are non-canonical secondary nucleic acid structures found in the transcriptome. They play crucial roles in gene regulation by interacting with G4-binding proteins (G4BPs) in cells. rG4-G4BP complexes have been associated with human diseases, making them important targets for drug development. Generating innovative tools to disrupt rG4-G4BP interactions will provide a unique opportunity to explore new biological mechanisms and potentially treat related diseases. Here, we have rationally designed and developed a series of rG4-based proteolytic targeting chimeras (rG4-PROTACs) aimed at degrading G4BPs, such as DHX36, a specific G4BP that regulates gene expression by binding to and unraveling rG4 structures in messenger RNAs (mRNAs). Our comprehensive data and systematic analysis reveals that rG4-PROTACs predominantly and selectively degrade DHX36 through a proteosome-dependent mechanism, which promotes the formation of the rG4 structure in mRNA, leading to the translation inhibition of rG4-containing transcripts. Notably, rG4-PROTACs inhibit rG4-mediated APP protein expression, and impact the proliferative capacity of skeletal muscle stem cells by negatively regulating Gnai2 protein expression. In summary, rG4-PROTACs provide a new avenue to understand rG4-G4BP interactions and the biological implications of dysregulated G4BPs, promoting the development of PROTACs technology based on the non-canonical structure of nucleic acids.RNA G-quadruplex structure-based PROTACs for targeted DHX36 protein degradation and gene activity modulation in mammalian cells.Zhang Kun K, Nie Qichang Q, Li Maolin M, Chen Xiaona X, Zhong Liting L, Dai Tianle T, Guo Xiaofan X, Zhao Haizhou H, Lau Terrence Chi-Kong TC, Wang Huating H, Chen Shuo-Bin SB, Kwok Chun Kit CKfalseProteomic analysis of rG4_A selectively degraded proteins through the proteasomeTo explore the effects of rG4-PROTACs on the whole proteome, Hela cells were treated with blank (empty transfection control), rG4 mut_A, rG4_A, or rG4_A plus MG132, and a proteomic analysis was included in the subprojectThu Nov 21 00:00:00 GMT 2024PXD058113960639883012