Understanding transcription: One molecule at a time
Netherlands Cancer Institute, Amsterdam, NL
@CECAD, Lecture Hall (ground floor)
Host: Prof. Andreas Beyer, Institute for Genetics, CECAD, University of Cologne
ABSTRACT
We owe a lot of our understanding of the translation machinery to small molecule probes. Since large parts of the protein synthesis apparatus are essential and difficult to manipulate through genetics or molecular biology, small molecule modulators provide potent tools for dissecting specific steps in the production of new proteins. Advances in DNA sequencing technology now enable a comprehensive understanding of the physiological impact of translation perturbation. Using ribosome profiling we could demonstrate that the small marine natural product girolline (Giro) acts as a sequence-selective modulator of translation elongation factor eIF5A. Giro discourages eIF5A binding to the ribosome and leads to ribosomal stalling on difficult to translate sequence elements, including stretches containing poly-proline or AAA-encoded lysine. Giro-induced ribosome stalling triggers the ribosome-associated quality control (RQC) pathway and at least part of Giro’s cytotoxicity derives from premature activation of quality control pathways. Using CRISPR/Cas knock-out screening we were furthermore able to identify several cellular systems and quality control pathways impacted by eIF5A dysfunction. Therefore, we could not only introduce the first specific chemical probe into eIF5A activity but also follow the physiological impact of eIF5A perturbation on a cellular system.
ABOUT DR. LENSTRA
Dr. Tineke Lenstra is a group leader at the Netherlands Cancer Institute and Oncode Institute, focusing on the regulatory mechanisms of stochastic transcription in single eukaryotic cells. She has a long-standing interest in understanding transcription regulation. She was trained as a biomedical scientist at Utrecht University and did her PhD in the laboratory of Frank Holstege at University Medical Centre Utrecht, where she used genome-wide expression analysis to study transcription regulatory complexes. During her postdoc in laboratory of Daniel Larson at the National Cancer Institute in Bethesda, USA, she gained expertise in cutting-edge single-molecule imaging techniques to visualize the stochastic behavior of individual regulatory protein molecules and the dynamics of transcription inside living cells. In 2016, she established an independent group at the Netherlands Cancer Institute (NKI) in Amsterdam, and in 2019, she joined Oncode Institute. For her work, she has received a number of awards, including the NWO Aspasia Award (2023), the EMBO Young Investigator Program (2023), the KNAW early career award (2020) and the NVBMB prize (2018). Major grants include the NWO Talent Program VIDI grant, Oncode Institute, and the ERC starting and consolidator grants.