Table 1.
Moonlighting roles of components of protein quality control machinery in intracellular protozoan parasites
| Protein family | Functions | Ref. |
|---|---|---|
| sHSPs |
Involved in cellular adhesion and migration Also promotes thermotolerance and intracellular survival Stage-specific expression may influence cellular decision of proliferation and differentiation. |
Montagna et al. 2012; Hombach et al. 2014; (Perez-Morales and Espinoza 2015 |
| Histone chaperones |
Folding, assembly, nuclear import, and degradation of histones DNA unwinding during replication, recombination, and repair Helps in recruitment of epigenetic machinery on DNA Survival and fertility of gametes |
Navadgi et al. 2006; Laurentino et al. 2011; Scher et al. 2012; Alsford and Horn 2012 |
| HSP40 |
Potential roles in parasite protein trafficking and export of virulence factors |
Botha et al. 2007; Kulzer et al. 2010; Pei et al. 2007 |
| Chaperonin | Suggested to play a role in protein trafficking and drug resistance | Mok et al. 2015 |
| HSP70 superfamily | Involved in nuclear and organellar genome maintenance, [Fe-S] cluster biogenesis and assembly, modulation of immune response, involved in trafficking of virulence factors, antigen presentation | Kumar et al. 2010; Týč et al. 2015; Lukes and Basu 2015; Dobbin et al. 2002 |
| HSP90 |
Interaction with epigenetic modifiers, differentiation, probable role in drug resistance Maintenance of telomere homeostasis and serving as an evolutionary capacitor# |
Pallavi et al. 2010; Echeverria et al. 2010; Kaur et al. 2017; |
| AAA+ proteins |
Includes Clp proteases and HSP100 disaggregase machinery Also implicated in parasite survival, virulence, and protein export |
Hübel et al. 1997; de Koning-Ward et al. 2009 |
| Ubiquitin proteasome system |
Dampening of host immune response, influences host signaling through post-translational modification, and is also associated with drug resistance. |
Loureiro and Ploegh 2006; Maculins et al. 2016; Haldar et al. 2018 |
| Autophagy related proteins | Involved in organelle biogenesis | Bansal et al. 2017; Walczak et al. 2018 |
| Stress-activated proteins | Generally perform metabolic functions, but during exposure to stress, they also exhibit ATP-independent chaperone activity and undergo conformational rearrangements | Teixeira et al. 2019 |