Identification and characterisation of transcriptional regulators through proximity interaction mapping in two distinct systems
[eng] Transcriptional regulation is a multifaceted and fundamental process, which underpins normal physiology, and its dysregulation is associated to numerous pathologies. Using two inherently different transcriptional programmes, we probed the complex nature of the components and systems that gover...
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| Tipo de recurso: | tesis doctoral |
| Fecha de publicación: | 2022 |
| País: | España |
| Institución: | Universidad de Barcelona |
| Repositorio: | Dipòsit Digital de la UB |
| OAI Identifier: | oai:diposit.ub.edu:2445/192880 |
| Acceso en línea: | https://hdl.handle.net/2445/192880 http://hdl.handle.net/10803/687546 |
| Access Level: | acceso abierto |
| Palabra clave: | Biologia molecular Oncologia Transcripció genètica Càncer de pròstata Molecular biology Oncology Genetic transcription Prostate cancer |
| Sumario: | [eng] Transcriptional regulation is a multifaceted and fundamental process, which underpins normal physiology, and its dysregulation is associated to numerous pathologies. Using two inherently different transcriptional programmes, we probed the complex nature of the components and systems that govern their organisation. 1) The differentiation of Multiciliated cells (MCCs) requires the sequential action of the atypical transcriptional activators GEMC1 and MCIDAS. Activation of the pathway results in the projection of dozens to hundreds of motile cilia from the apical surface of MCCs to promote the movement of fluids in the mammalian brain, airway or reproductive organs. How these factors operate and the extent to which they play redundant functions remains poorly understood. Here, we demonstrate that the transcriptional targets and proximal proteomes of GEMC1 and MCIDAS are highly similar. However, we identified distinct interactions with SWI/SNF subcomplexes; GEMC1 interacts primarily with the ARID1A containing BAF complex and MCIDAS with the BRD9 containing ncBAF complex. Inhibition of BRD9 impaired MCIDAS-mediated activation of several target genes and compromised MCC differentiation in two Multiciliogenesis models. We further began to decipher the regulatory role CCNO, a cyclin expressed during MCC differentiation, has on this complex process, highlighting a number of important interactions. Our data suggests that the differential engagement of distinct SWI/SNF subcomplexes by GEMC1 and MCIDAS is required for MCC-specific transcriptional regulation and that CCNO regulates the process. 2) Large transcriptional apparatus can form transcriptional condensates, in a process known as phase separation, aberrations of which can affect the activity of genes responsible for human disease. Castration resistant prostate cancer is a disease that is driven by the pathogenic Androgen Receptor, a transcription factor which is currently thought to be “undruggable”. Here we demonstrate, that by altering the aromaticity of the AR through tyrosine mutations, we can impair the formation of condensates that results in defective translocation, protein interactions and transcriptional activity. Furthermore, using a panel of novel small molecule inhibitors, we could perturb AR phase separation and arrest its protein interactions and functions in tumour development. |
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