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Sanz-Murillo, M.

Publications and source records attributed to Sanz-Murillo, M..

2 recordsLinked to original sources

Type-II kinase inhibitors that target Parkinson's Disease-associated LRRK2

Aberrant increases in kinase activity of leucine-rich repeat kinase 2 (LRRK2) are associated with Parkinsons disease (PD). Numerous LRRK2-selective type-I kinase inhibitors have been developed and some have entered clinical trials. In this study, we present the first LRRK2-selective type-II kinase inhibitors. Targeting the inactive conformation of LRRK2 is functionally distinct from targeting the active-like conformation using type-I inhibitors. We designed these inhibitors using a combinatorial chemistry approach fusing selective LRRK2 type-I and promiscuous type-II inhibitors by iterative cycles of synthesis supported by structural biology and activity testing. Our current lead structures are selective and potent LRRK2 inhibitors. Through cellular assays, cryo-electron microscopy structural analysis, and in vitro motility assays, we show that our inhibitors stabilize the open, inactive kinase conformation. These new conformation-specific compounds will be invaluable as tools to study LRRK2s function and regulation, and expand the potential therapeutic options for PD.

cell biology↗

Cryo-EM uncovers a sequential mechanism for RNA polymerase I pausing and stalling at abasic DNA lesions

RNA polymerase I (Pol I) transcribes ribosomal DNA (rDNA) to produce the rRNA precursor, which accounts for up to 60% of the total transcriptional activity in growing cells. Pol I monitors rDNA integrity and influences cell survival, but little is known about how this enzyme processes abasic DNA lesions. Here, we report electron cryo-microscopy (cryo-EM) structures of Pol I at different stages of stalling at abasic sites, supported by in vitro transcription studies. Our results show that templating abasic sites can slow nucleotide addition by base sandwiching between the RNA 3-end and the Pol I bridge helix. However, the presence of a templating abasic site induces opening of the Pol I cleft for either enzyme dissociation from DNA or for access of A12-Ct into the active site to stimulate RNA cleavage. Nucleotide addition opposite the lesion induces an early translocation intermediate that is different from previously-described RNA polymerase paused states, as DNA bases in the hybrid tilt to form hydrogen bonds with the newly-added RNA base. While in this state nucleotide addition is strongly disfavoured, intrinsic Pol I RNA cleavage activity acts as a failsafe mechanism to minimize lesion bypass. Our results uncover a two-step mechanism leading to persistent Pol I stalling after nucleotide addition opposite Ap sites, which is distinct from arrest by CPD lesions and from Pol II blockage at Ap sites.

molecular biology↗