Heat Shock Factor 2 Protects against Proteotoxicity by Maintaining Cell-Cell Adhesion Jenny Joutsen, Alejandro Jose da Silva, Jens Christian Luoto, Marek Andrzej Budzynski, Anna Serafia Nylund, Aurélie de Thonel, Jean-Paul Concordet, Valérie Mezger, Délara Sabéran-Djoneidi, Eva Henriksson, et al. To cite this version: Jenny Joutsen, Alejandro Jose da Silva, Jens Christian Luoto, Marek Andrzej Budzynski, Anna Serafia Nylund, et al.. Heat Shock Factor 2 Protects against Proteotoxicity by Maintaining Cell-Cell Adhesion. Cell Reports, Elsevier Inc, 2020, 30 (2), pp.583-597.e6. 10.1016/j.celrep.2019.12.037. hal-02929926 HAL Id: hal-02929926 https://hal.archives-ouvertes.fr/hal-02929926 Submitted on 6 Jan 2021 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Article Heat Shock Factor 2 Protects against Proteotoxicity by Maintaining Cell-Cell Adhesion Graphical Abstract Authors Jenny Joutsen, Alejandro Jose Da Silva, Jens Christian Luoto, ..., De´ lara Sabe´ ran-Djoneidi, Eva Henriksson, Lea Sistonen Correspondence lea.sistonen@abo.fi In Brief Joutsen et al. show that heat shock factor 2 (HSF2) is essential for cell survival during prolonged proteotoxicity. Lack of HSF2 leads to marked misregulation of cadherin superfamily genes and functional impairment of cell-cell adhesion. Cell-cell adhesion is found to be a key determinant of proteotoxic stress resistance. Highlights d HSF2 is required to maintain cell-cell adhesion d HSF2 deficiency leads to downregulation of cadherin superfamily genes d Impaired cell-cell adhesion sensitizes cells to prolonged proteotoxic stress d Cadherin-mediated cell-cell adhesion is a survival determinant upon proteotoxicity Joutsen et al., 2020, Cell Reports 30, 583–597 January 14, 2020 ª 2019 The Author(s). https://doi.org/10.1016/j.celrep.2019.12.037 Cell Reports Article Heat Shock Factor 2 Protects against Proteotoxicity by Maintaining Cell-Cell Adhesion Jenny Joutsen,1,2,7 Alejandro Jose Da Silva,1,2,7 Jens Christian Luoto,1,2 Marek Andrzej Budzynski,1,2 Anna Serafia Nylund,1,2 Aurelie de Thonel,3,4,5 Jean-Paul Concordet,6 Vale´ rie Mezger,3,4,5 De´ lara Sabe´ ran-Djoneidi,3,4,5 Eva Henriksson,1,2 and Lea Sistonen1,2,8,* 1Faculty of Science and Engineering, Cell Biology, A˚ bo Akademi University, Tykisto¨ katu 6, 20520 Turku, Finland 2Turku Bioscience Centre, University of Turku and A˚ bo Akademi University, Tykisto¨ katu 6, 20520 Turku, Finland 3CNRS, UMR 7216 ‘‘Epigenetic and Cell Fate,’’ 75250 Paris Cedex 13, France 4University of Paris Diderot, Sorbonne Paris Cite´ , 75250 Paris Cedex 13, France 5De´ partement Hospitalo-Universitaire DHU PROTECT, Paris, France 6INSERM U1154, CNRS UMR 7196, Muse´ um National d’Histoire Naturelle, Paris, France 7These authors contributed equally 8Lead Contact *Correspondence: lea.sistonen@abo.fi https://doi.org/10.1016/j.celrep.2019.12.037 SUMMARY mediated by heat shock transcription factors (HSFs; Joutsen and Sistonen, 2019). Upon activation, HSFs oligomerize, accu- Maintenance of protein homeostasis, through induc- mulate in the nucleus, and bind to their target heat shock ele- ible expression of molecular chaperones, is essential ments (HSEs) at multiple genomic loci (Vihervaara et al., 2013, for cell survival under protein-damaging conditions. 2017; Mahat et al., 2016). The canonical HSF target genes The expression and DNA-binding activity of heat encode molecular chaperones, such as heat shock proteins shock factor 2 (HSF2), a member of the heat shock (HSPs), which assist in the maintenance of a correct protein transcription factor family, increase upon exposure folding environment by refolding the misfolded proteins or di- recting them to protein degradation machineries (Hartl et al., to prolonged proteotoxicity. Nevertheless, the spe- 2011). In addition, HSFs are important in a variety of other phys- cific roles of HSF2 and the global HSF2-dependent iological and pathological processes and the repertoire of HSF gene expression profile during sustained stress target genes has been shown to extend beyond the HSPs have remained unknown. Here, we found that HSF2 (Hahn et al., 2004; A˚ kerfelt et al., 2010; Gonsalves et al., 2011; is critical for cell survival during prolonged proteo- Mendillo et al., 2012; Riva et al., 2012; Bjo¨ rk et al., 2016; Li toxicity. Strikingly, our RNA sequencing (RNA-seq) et al., 2016). analyses revealed that impaired viability of HSF2- The human genome encodes six HSF family members (HSF1, deficient cells is not caused by inadequate induction HSF2, HSF4, HSF5, HSFX, and HSFY), of which HSF1 and HSF2 of molecular chaperones but is due to marked down- are the most extensively studied (Joutsen and Sistonen, 2019). regulation of cadherin superfamily genes. We Although these factors are homologous in their DNA-binding do- demonstrate that HSF2-dependent maintenance of mains, they share only a few similarities in the tissue expression patterns, regulatory mechanisms, and signals that stimulate their cadherin-mediated cell-cell adhesion is required for activity (Jaeger et al., 2016; Gomez-Pastor et al., 2018). HSF1 is protection against stress induced by proteasome in- essential for HSP expression and cell survival under acute stress hibition. This study identifies HSF2 as a key regulator conditions (Joutsen and Sistonen, 2019). HSF2 is an unstable of cadherin superfamily genes and defines cell-cell protein and its expression is highly context dependent, fluctu- adhesion as a determinant of proteotoxic stress ating in different cell and tissue types (Sarge et al., 1991; Alastalo resistance. et al., 1998), developmental stages (Mezger et al., 1994; Rallu et al., 1997), and during the cell cycle (Elsing et al., 2014). Conse- INTRODUCTION quently, regulation of HSF2 protein levels has been considered to be the main determinant of its DNA-binding capacity (Mathew The cells in a human body are constantly exposed to environ- et al., 1998; Budzynski and Sistonen, 2017). Interestingly, the mental stressors, which challenge the maintenance of protein DNA-binding activity of HSF2 increases in cells exposed to lac- homeostasis, also called proteostasis. To survive insults that tacystin- or MG132-induced proteasome inhibition (Kawazoe disturb proteostasis, cells rely on a selection of protective mech- et al., 1998; Mathew et al., 1998; Pirkkala et al., 2000), indicating anisms that can be launched upon stress exposures. The heat that HSF2 can respond to proteostasis disruption. Nevertheless, shock response is a well-conserved stress protective pathway the molecular details of the activation mechanisms of HSF2 are that is induced in response to cytosolic protein damage and currently not conclusively understood. Cell Reports 30, 583–597, January 14, 2020 ª 2019 The Author(s). 583 This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Figure 1. HSF2 Is Upregulated upon Prolonged Bortezomib (BTZ) Treatment (A) Immunoblot analysis of HSF2 expression. U2OS WT cells were treated with indicated concentrations of BTZ for 6 or 22 h. Control (C) cells were treated with DMSO. Tubulin was used as a loading control. (B) Confocal microscopy images of HSF2 immunofluorescence staining. U2OS WT cells were plated on coverslips and treated with 25 nM BTZ for 6, 10, or 22 h. Control cells were treated with DMSO. Samples were fixed and stained with anti-HSF2 antibody. DAPI was used for DNA detection. The overlay of HSF2 and DAPI maximum intensity projection signals is shown in merge. Scale bar, 100 mm. (C) Immunoblot analysis of HSF2 in subcellular fractions. U2OS WT cells were treated with 25 nM BTZ for 6 and 22 h. Control cells were treated with DMSO. Wc, whole cell fraction; Cy, cytoplasmic fraction; and Nu, nuclear fraction. Lamin A/C and Tubulin were used as fractionation controls. The ubiquitin-proteasome system is one of the main cellular In this study, we show that HSF2 is critical for survival of cells mechanisms regulating protein turnover, thereby affecting multi- during prolonged proteasome inhibition. To our surprise, the ple aspects of cell physiology, such as signal transduction and genome-wide expression analyses revealed that HSF2 disrup- apoptosis (Hershko and Ciechanover, 1998; Varshavsky, 2012). tion results in a profound downregulation of genes belonging Due to the fundamental function in cell physiology, the protea- to the cadherin superfamily and subsequent functional impair- some complex has emerged as an important target for anti-can- ment of cell-cell adhesion. Furthermore, we show that failure to cer therapy (Deshaies, 2014). The most common drug to inhibit form adequate cadherin-mediated cell-cell adhesion contacts proteasome function is bortezomib (BTZ; PS-341, VELCADE), predisposes cells to proteasome inhibition-induced cell death. which is currently used as a standard treatment in hematological These results identify HSF2 as a key regulator of cadherin genes. malignancies (Chen et al., 2011). BTZ is a dipeptide boronic acid Taken together, we show that by maintaining cadherin-mediated derivative that