Abstract
Small heat shock proteins (sHsps) exhibit an ATP-independent chaperone activity to prevent the aggregation of misfolded proteins in vitro. The seemingly conflicting presence of sHsps in insoluble protein aggregates in cells obstructs a precise definition of sHsp function in proteostasis networks. Recent findings specify sHsp activities in protein quality control systems. The sHsps of yeast, Hsp42 and Hsp26, interact with early unfolding intermediates of substrates, keeping them in a ready-to-refold conformation close to the native state. This activity facilitates substrate refolding by ATP-dependent Hsp70-Hsp100 disaggregating chaperones. Hsp42 can actively sequester misfolded proteins and promote their deposition at specific cellular sites. This aggregase activity represents a cytoprotective protein quality control strategy. The aggregase function of Hsp42 controls the formation of cytosolic aggregates (CytoQs) under diverse stress regimes and can be reconstituted in vitro, demonstrating that Hsp42 is necessary and sufficient to promote protein aggregation. Substrates sequestered at CytoQs can be dissociated by Hsp70-Hsp100 disaggregases for subsequent triage between refolding and degradation pathways or are targeted for destruction by selective autophagy termed proteophagy.
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References
Aguilaniu H, Gustafsson L, Rigoulet M, Nystrom T (2003) Asymmetric inheritance of oxidatively damaged proteins during cytokinesis. Science 299:1751–1753
Alberti S, Halfmann R, King O, Kapila A, Lindquist S (2009) A systematic survey identifies prions and illuminates sequence features of prionogenic proteins. Cell 137:146–158. doi:10.1016/j.cell.2009.02.044
Allen SP, Polazzi JO, Gierse JK, Easton AM (1992) Two novel heat shock genes encoding proteins produced in response to heterologous protein expression in Escherichia coli. J Bacteriol 174:6938–6947
Arrasate M, Mitra S, Schweitzer ES, Segal MR, Finkbeiner S (2004) Inclusion body formation reduces levels of mutant huntingtin and the risk of neuronal death. Nature 431:805–810. doi:10.1038/nature02998
Arrigo AP, Suhan JP, Welch WJ (1988) Dynamic changes in the structure and intracellular locale of the mammalian low-molecular-weight heat shock protein. Mol Cell Biol 8:5059–5071
Basha E et al (2013) An unusual dimeric small heat shock protein provides insight into the mechanism of this class of chaperones. J Mol Biol doi. doi:10.1016/j.jmb.2013.02.011
Basha E, O'Neill H, Vierling E (2012) Small heat shock proteins and alpha-crystallins: dynamic proteins with flexible functions. Trends Biochem Sci 37:106–117. doi:10.1016/j.tibs.2011.11.005
Bepperling A et al (2012) Alternative bacterial two-component small heat shock protein systems. Proc Natl Acad Sci U S A 109:20407–20412. doi:10.1073/pnas.1209565109
Carra S, Seguin SJ, Landry J (2008) HspB8 and Bag3: a new chaperone complex targeting misfolded proteins to macroautophagy. Autophagy 4:237–239
Cashikar AG, Duennwald M, Lindquist SL (2005) A chaperone pathway in protein disaggregation. Hsp26 alters the nature of protein aggregates to facilitate reactivation by Hsp104. J Biol Chem 280:23869–23875
Chen B, Retzlaff M, Roos T, Frydman J (2011) Cellular strategies of protein quality control. Cold Spring Harb Perspect Biol 3:a004374. doi:10.1101/cshperspect.a004374
Cheng G, Basha E, Wysocki VH, Vierling E (2008) Insights into small heat shock protein and substrate structure during chaperone action derived from hydrogen/deuterium exchange and mass spectrometry. J Biol Chem 283:26634–26642. doi:10.1074/jbc.M802946200
Cheng IH et al (2007) Accelerating amyloid-beta fibrillization reduces oligomer levels and functional deficits in Alzheimer disease mouse models. J Biol Chem 282:23818–23828. doi:10.1074/jbc.M701078200
Coelho M, Lade SJ, Alberti S, Gross T, Tolic IM (2014) Fusion of protein aggregates facilitates asymmetric damage segregation. PLoS Biol 12:e1001886. doi:10.1371/journal.pbio.1001886
Cohen E, Bieschke J, Perciavalle RM, Kelly JW, Dillin A (2006) Opposing activities protect against age-onset proteotoxicity. Science 313:1604–1610
Cohen E et al (2009) Reduced IGF-1 signaling delays age-associated proteotoxicity in mice. Cell 139:1157–1169. doi:10.1016/j.cell.2009.11.014
Ehrnsperger M, Gräber S, Gaestel M, Buchner J (1997) Binding of non-native protein to Hsp25 during heat shock creates a reservoir of folding intermediates for reactivation. EMBO J 16:221–229
Escusa-Toret S, Vonk WI, Frydman J (2013) Spatial sequestration of misfolded proteins by a dynamic chaperone pathway enhances cellular fitness during stress. Nat Cell Biol 15:1231–1243. doi:10.1038/ncb2838
Friedrich KL, Giese KC, Buan NR, Vierling E (2004) Interactions between small heat shock protein subunits and substrate in small heat shock protein-substrate complexes. J Biol Chem 279:1080–1089
Fu X, Shi X, Yin L, Liu J, Joo K, Lee J, Chang Z (2013) Small heat shock protein IbpB acts as a robust chaperone in living cells by hierarchically activating its multi-type substrate-binding residues. J Biol Chem 288:11897–11906. doi:10.1074/jbc.M113.450437
Fuchs M, Poirier DJ, Seguin SJ, Lambert H, Carra S, Charette SJ, Landry J (2009) Identification of the key structural motifs involved in HspB8/HspB6-Bag3 interaction. Biochem J 425:245–255. doi:10.1042/BJ20090907
Gallina I et al (2015) Cmr1/WDR76 defines a nuclear genotoxic stress body linking genome integrity and protein quality control. Nat Commun 6:6533. doi:10.1038/ncomms7533
Giese KC, Vierling E (2002) Changes in oligomerization are essential for the chaperone activity of a small heat shock protein in vivo and in vitro. J Biol Chem 277:46310–46318
Han MJ, Park SJ, Park TJ, Lee SY (2004) Roles and applications of small heat shock proteins in the production of recombinant proteins in Escherichia coli. Biotechnol Bioeng 88:426–436. doi:10.1002/bit.20227
Hartl FU, Bracher A, Hayer-Hartl M (2011) Molecular chaperones in protein folding and proteostasis. Nature 475:324–332. doi:10.1038/nature10317
Haslbeck M, Franzmann T, Weinfurtner D, Buchner J (2005a) Some like it hot: the structure and function of small heat-shock proteins. Nat Struct Mol Biol 12:842–846. doi:10.1038/nsmb993
Haslbeck M, Ignatiou A, Saibil H, Helmich S, Frenzl E, Stromer T, Buchner J (2004) A domain in the N-terminal part of Hsp26 is essential for chaperone function and oligomerization. J Mol Biol 343:445–455. doi:10.1016/j.jmb.2004.08.048
Haslbeck M, Miess A, Stromer T, Walter S, Buchner J (2005b) Disassembling protein aggregates in the yeast cytosol. The cooperation of Hsp26 with Ssa1 and Hsp104. J Biol Chem 280:23861–23868. doi:10.1074/jbc.M502697200
Hill SM et al (2016) Asymmetric inheritance of aggregated proteins and age reset in yeast are regulated by Vac17-dependent vacuolar functions. Cell Rep 16:826–838. doi:10.1016/j.celrep.2016.06.016
Jakob U, Gaestel M, Engel K, Buchner J (1993) Small heat shock proteins are molecular chaperones. J Biol Chem 268:1517–1520
Jaya N, Garcia V, Vierling E (2009) Substrate binding site flexibility of the small heat shock protein molecular chaperones. Proc Natl Acad Sci U S A 106:15604–15609. doi:10.1073/pnas.0902177106
Johnston JA, Ward CL, Kopito RR (1998) Aggresomes: a cellular response to misfolded proteins. J Cell Biol 143:1883–1898
Kaganovich D, Kopito R, Frydman J (2008) Misfolded proteins partition between two distinct quality control compartments. Nature 454:1088–1095
Kampinga HH, Brunsting JF, Stege GJ, Konings AW, Landry J (1994) Cells overexpressing Hsp27 show accelerated recovery from heat-induced nuclear protein aggregation. Biochem Biophys Res Commun 204:1170–1177. doi:10.1006/bbrc.1994.2586
Kawaguchi Y, Kovacs JJ, McLaurin A, Vance JM, Ito A, Yao TP (2003) The deacetylase HDAC6 regulates aggresome formation and cell viability in response to misfolded protein stress. Cell 115:727–738
Krajewski SS, Joswig M, Nagel M, Narberhaus F (2014) A tricistronic heat shock operon is important for stress tolerance of Pseudomonas putida and conserved in many environmental bacteria. Environ Microbiol 16:1835–1853. doi:10.1111/1462-2920.12432
Kriehuber T, Rattei T, Weinmaier T, Bepperling A, Haslbeck M, Buchner J (2010) Independent evolution of the core domain and its flanking sequences in small heat shock proteins. FASEB J 24:3633–3642. doi:10.1096/fj.10-156992
Kumar R, Nawroth PP, Tyedmers J (2016) Prion aggregates are recruited to the insoluble protein deposit (IPOD) via myosin 2-based vesicular transport. PLoS Genet 12:e1006324. doi:10.1371/journal.pgen.1006324
Laskowska E, Wawrzynow A, Taylor A (1996) IbpA and IbpB, the new heat-shock proteins, bind to endogenous Escherichia coli proteins aggregated intracellularly by heat shock. Biochimie 78:117–122
Lee GJ, Roseman AM, Saibil HR, Vierling E (1997) A small heat shock protein stably binds heat-denatured model substrates and can maintain a substrate in a folding-competent state. EMBO J 16:659–671
Lee GJ, Vierling E (2000) A small heat shock protein cooperates with heat shock protein 70 systems to reactivate a heat-denatured protein. Plant Physiol 122:189–198
Lee U, Wie C, Escobar M, Williams B, Hong SW, Vierling E (2005) Genetic analysis reveals domain interactions of Arabidopsis Hsp100/ClpB and cooperation with the small heat shock protein chaperone system plant. Cell 17:559–571
Liu B, Larsson L, Caballero A, Hao X, Oling D, Grantham J, Nystrom T (2010) The polarisome is required for segregation and retrograde transport of protein aggregates. Cell 140:257–267. doi:10.1016/j.cell.2009.12.031
Lu K, Psakhye I, Jentsch S (2014) Autophagic clearance of polyQ proteins mediated by ubiquitin-Atg8 adaptors of the conserved CUET protein family. Cell 158:549–563. doi:10.1016/j.cell.2014.05.048
Malinovska L, Kroschwald S, Alberti S (2013) Protein disorder, prion propensities, and self-organizing macromolecular collectives. Biochim Biophys Acta 1834:918–931. doi:10.1016/j.bbapap.2013.01.003
Malinovska L, Kroschwald S, Munder MC, Richter D, Alberti S (2012) Molecular chaperones and stress-inducible protein-sorting factors coordinate the spatiotemporal distribution of protein aggregates. Mol Biol Cell 23:3041–3056. doi:10.1091/mbc.E12-03-0194
Marshall RS, McLoughlin F, Vierstra RD (2016) Autophagic turnover of inactive 26S proteasomes in yeast is directed by the ubiquitin receptor Cue5 and the Hsp42. Chaperone Cell Rep 16:1717–1732. doi:10.1016/j.celrep.2016.07.015
McLoughlin F, Basha E, Fowler ME, Kim M, Bordowitz J, Katiyar-Agarwal S, Vierling E (2016) Class I and II small heat-shock proteins protect protein translation factors during heat stress. Plant Physiol. doi:10.1104/pp.16.00536
Miller SB et al (2015b) Compartment-specific aggregases direct distinct nuclear and cytoplasmic aggregate deposition. EMBO J 34:778–797. doi:10.15252/embj.201489524
Miller SB, Mogk A, Bukau B (2015a) Spatially organized aggregation of misfolded proteins as cellular stress defense strategy. J Mol Biol 427:1564–1574. doi:10.1016/j.jmb.2015.02.006
Mogk A, Deuerling E, Vorderwulbecke S, Vierling E, Bukau B (2003a) Small heat shock proteins, ClpB and the DnaK system form a functional triade in reversing protein aggregation. Mol Microbiol 50:585–595
Mogk A, Schlieker C, Friedrich KL, Schönfeld H-J, Vierling E, Bukau B (2003b) Refolding of substrates bound to small Hsps relies on a disaggregation reaction mediated most efficiently by ClpB/DnaK. J Biol Chem 278:31033–31042
Mogk A, Tomoyasu T, Goloubinoff P, Rüdiger S, Röder D, Langen H, Bukau B (1999) Identification of thermolabile E. coli proteins: prevention and reversion of aggregation by DnaK and ClpB. EMBO J 18:6934–6949
Nillegoda NB et al (2015) Crucial HSP70 co-chaperone complex unlocks metazoan protein disaggregation. Nature 524:247–251. doi:10.1038/nature14884
Peters LZ, Karmon O, David-Kadoch G, Hazan R, Yu T, Glickman MH, Ben-Aroya S (2015) The protein quality control machinery regulates its misassembled proteasome subunits. PLoS Genet 11:e1005178. doi:10.1371/journal.pgen.1005178
Protter DS, Parker R (2016) Principles and properties of stress granules. Trends Cell Biol 26:668–679. doi:10.1016/j.tcb.2016.05.004
Queitsch C, Hong SW, Vierling E, Lindquist S (2000) Heat shock protein 101 plays a crucial role in thermotolerance in Arabidopsis. Plant Cell 12:479–492
Rampelt H, Kirstein-Miles J, Nillegoda NB, Chi K, Scholz SR, Morimoto RI, Bukau B (2012) Metazoan Hsp70 machines use Hsp110 to power protein disaggregation. EMBO J 31:4221–4235. doi:10.1038/emboj.2012.264
Ratajczak E, Zietkiewicz S, Liberek K (2009) Distinct activities of Escherichia coli small heat shock proteins IbpA and IbpB promote efficient protein disaggregation. J Mol Biol 386:178–189. doi:10.1016/j.jmb.2008.12.009
Rauch JN, Tse E, Freilich R, Mok SA, Makley LN, Southworth DR, Gestwicki JE (2016) BAG3 is a modular, scaffolding protein that physically links heat shock protein 70 (Hsp70) to the small heat shock proteins. J Mol Biol. doi:10.1016/j.jmb.2016.11.013
Rujano MA et al (2006) Polarised asymmetric inheritance of accumulated protein damage in higher eukaryotes. PLoS Biol 4:e417
Saarikangas J, Barral Y (2015) Protein aggregates are associated with replicative aging without compromising protein quality control. eLife 4:e06197. doi:10.7554/eLife.06197
Sanchez Y, Lindquist SL (1990) HSP104 required for induced thermotolerance. Science 248:1112–1115
Shiber A, Breuer W, Brandeis M, Ravid T (2013) Ubiquitin conjugation triggers misfolded protein sequestration into quality-control foci when Hsp70 chaperone levels are limiting. Mol Biol Cell 24:2076–2087. doi:10.1091/mbc.E13-01-0010
Song J et al (2014) Essential genetic interactors of SIR2 required for spatial sequestration and asymmetrical inheritance of protein aggregates. PLoS Genet 10:e1004539. doi:10.1371/journal.pgen.1004539
Specht S, Miller SB, Mogk A, Bukau B (2011) Hsp42 is required for sequestration of protein aggregates into deposition sites in Saccharomyces cerevisiae. J Cell Biol 195:617–629. doi:10.1083/jcb.201106037
Spokoini R, Moldavski O, Nahmias Y, England JL, Schuldiner M, Kaganovich D (2012) Confinement to organelle-associated inclusion structures mediates asymmetric inheritance of aggregated protein in budding yeast. Cell Rep 2:738–747. doi:10.1016/j.celrep.2012.08.024
Squires CL, Pedersen S, Ross BM, Squires C (1991) ClpB is the Escherichia coli heat shock protein F84.1. J Bacteriol 173:4254–4262
Stengel F et al (2012) Dissecting heterogeneous molecular chaperone complexes using a mass spectrum deconvolution approach. Chem Biol 19:599–607. doi:10.1016/j.chembiol.2012.04.007
Stengel F et al (2010) Quaternary dynamics and plasticity underlie small heat shock protein chaperone function. Proc Natl Acad Sci U S A 107:2007–2012. doi:10.1073/pnas.0910126107
Tyedmers J, Mogk A, Bukau B (2010) Cellular strategies for controlling protein aggregation. Nat Rev Mol Cell Biol 11:777–788. doi:10.1038/nrm2993
Ungelenk S et al. (2016) Small heat shock proteins sequester misfolding proteins in near-native conformation for cellular protection and efficient refolding Nature communications in press
Veinger L, Diamant S, Buchner J, Goloubinoff P (1998) The small heat shock protein IbpB from Escherichia coli stabilizes stress-denatured proteins for subsequent refolding by a multichaperone network. J Biol Chem 273:11032–11037
Vos MJ, Kanon B, Kampinga HH (2009) HSPB7 is a SC35 speckle resident small heat shock protein. Biochim Biophys Acta 1793:1343–1353. doi:10.1016/j.bbamcr.2009.05.005
Walther DM et al (2015) Widespread proteome remodeling and aggregation in aging C. elegans. Cell 161:919–932. doi:10.1016/j.cell.2015.03.032
Wolfe KJ, Ren HY, Trepte P, Cyr DM (2013) The Hsp70/90 cochaperone, Sti1, suppresses proteotoxicity by regulating spatial quality control of amyloid-like proteins. Mol Biol Cell doi. doi:10.1091/mbc.E13-06-0315
Zhou C et al (2014) Organelle-based aggregation and retention of damaged proteins in asymmetrically dividing cells. Cell 159:530–542
Acknowledgements
We thank Chi-ting Ho, Maria Khokhrina, and Tomas Grousl for critical reading of the manuscript. This work was supported by the Deutsche Forschungsgemeinschaft (SFB1036 project A8 to A. Mogk and B. Bukau).
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Mogk, A., Bukau, B. Role of sHsps in organizing cytosolic protein aggregation and disaggregation. Cell Stress and Chaperones 22, 493–502 (2017). https://doi.org/10.1007/s12192-017-0762-4
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DOI: https://doi.org/10.1007/s12192-017-0762-4