Large multiprotein complexes perform many essential functions in eukaryotic cells. My lab purifies, assays and determines structures of these macromolecular machines to understand their mechanisms. This often involves combination of several techniques or the development new methods.
Two possible projects are available in my group. The first project will address DNA repair mechanisms, specifically, the cellular response to DNA crosslinks and replication stress. The Fanconi Anaemia (FA) pathway is at the centre of DNA crosslink repair and involves a large multiprotein E3 ubiquitin ligase and a DNA clamp. Deregulation of this pathway can lead to human disease. We aim to understand the molecular mechanisms of the FA pathway.
The second, alternative project will address multiprotein complexes that regulate mRNA polyA tails. Almost every eukaryotic mRNA has a poly(A) tail at its 3ʹ-end. Poly(A) tails are added in the nucleus after endonucleolytic cleavage of the pre-mRNA and are required for export of mRNAs from the nucleus, for efficient translation and for mRNA stability. In the cytoplasm, poly(A) tails are shortened in a regulated manner to promote mRNA decay. We are studying the protein machineries that add and remove poly(A) tails. We aim to understand how these complexes are regulated, how they recognise mRNA, and the specific roles of subunits.
A wide range of techniques are employed by the group, including cryo-electron microscopy (cryo-EM), x-ray crystallography, single molecule studies, genetics, biophysics and biochemical assays.
Please contact me for more information and to discuss projects.
References
Passmore LA, Coller J. (2022) Roles of mRNA poly(A) tails in regulation of eukaryotic gene expression. Nat Rev Mol Cell Biol 23, 93–106
Boreikaite V, Passmore LA. (2023) 3′-End Processing of Eukaryotic mRNA: Machinery, Regulation, and Impact on Gene Expression. Ann Rev Biochem 92, 199-225. doi.org/10.1146/annurev-biochem-052521-012445
Rodríguez-Molina JB, O’Reilly FJ, Sheekey E, Maslen S, Skehel JM, Rappsilber J, Passmore LA. (2021) Mpe1 senses binding of pre-mRNA and controls 3ʹ-end processing by CPF. Mol Cell 82, 2490-2504
Boreikaite V, Elliott T, Chin J, Passmore LA. (2022) RBBP6 activates the pre-mRNA 3’-end processing machinery in humans. Genes Dev 36, 221–224
Alcón P, Shakeel S, Chen ZA, Rappsilber J, Patel KJ, Passmore LA (2020) FANCD2–FANCI is a clamp stabilized on DNA by monoubiquitination of FANCD2 during DNA repair Nature Struct Mol Biol 27:240-248. doi.org/10.1038/s41594-020-0380-1
Shakeel S, Rajendra E, Alcón P, O’Reilly F, Chorev DS, Maslen S, Degliesposti G, Russo CJ, He S, Hill CH, Skehel JM, Scheres SHW, Patel KJ, Rappsilber J, Robinson CV, Passmore LA (2019) Structure of the Fanconi anemia monoubiquitin ligase complex Nature 575:234-237 doi: 10.1038/s41586-019-1703-4