Publications by authors named "Michaela Remisova"

2 Publications

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TIRR inhibits the 53BP1-p53 complex to alter cell-fate programs.

Mol Cell 2021 Jun 6;81(12):2583-2595.e6. Epub 2021 May 6.

Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, MA 02115, USA; Department of Biological Chemistry & Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA. Electronic address:

53BP1 influences genome stability via two independent mechanisms: (1) regulating DNA double-strand break (DSB) repair and (2) enhancing p53 activity. We discovered a protein, Tudor-interacting repair regulator (TIRR), that associates with the 53BP1 Tudor domain and prevents its recruitment to DSBs. Here, we elucidate how TIRR affects 53BP1 function beyond its recruitment to DSBs and biochemically links the two distinct roles of 53BP1. Loss of TIRR causes an aberrant increase in the gene transactivation function of p53, affecting several p53-mediated cell-fate programs. TIRR inhibits the complex formation between the Tudor domain of 53BP1 and a dimethylated form of p53 (K382me2) that is poised for transcriptional activation of its target genes. TIRR mRNA expression levels negatively correlate with the expression of key p53 target genes in breast and prostate cancers. Further, TIRR loss is selectively not tolerated in p53-proficient tumors. Therefore, we establish that TIRR is an important inhibitor of the 53BP1-p53 complex.
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http://dx.doi.org/10.1016/j.molcel.2021.03.039DOI Listing
June 2021

AHNAK controls 53BP1-mediated p53 response by restraining 53BP1 oligomerization and phase separation.

Mol Cell 2021 Jun 6;81(12):2596-2610.e7. Epub 2021 May 6.

Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch, France; Institut National de la Santé et de la Recherche Médicale, U964, 67404 Illkirch, France; Centre National de Recherche Scientifique, UMR7104, 67404 Illkirch, France; Université de Strasbourg, 67081 Strasbourg, France. Electronic address:

p53-binding protein 1 (53BP1) regulates both the DNA damage response and p53 signaling. Although 53BP1's function is well established in DNA double-strand break repair, how its role in p53 signaling is modulated remains poorly understood. Here, we identify the scaffolding protein AHNAK as a G1 phase-enriched interactor of 53BP1. We demonstrate that AHNAK binds to the 53BP1 oligomerization domain and controls its multimerization potential. Loss of AHNAK results in hyper-accumulation of 53BP1 on chromatin and enhanced phase separation, culminating in an elevated p53 response, compromising cell survival in cancer cells but leading to senescence in non-transformed cells. Cancer transcriptome analyses indicate that AHNAK-53BP1 cooperation contributes to the suppression of p53 target gene networks in tumors and that loss of AHNAK sensitizes cells to combinatorial cancer treatments. These findings highlight AHNAK as a rheostat of 53BP1 function, which surveys cell proliferation by preventing an excessive p53 response.
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http://dx.doi.org/10.1016/j.molcel.2021.04.010DOI Listing
June 2021