Can heat shock protein 70 (HSP70) serve as biomarkers in Antarctica for future ocean acidification, warming and salinity stress?

Abstract

The Antarctic Peninsula is one of the fastest-warming places on Earth. Elevated sea water temperatures cause glacier and sea ice melting. When icebergs melt into the ocean, it “freshens” the saltwater around them, reducing its salinity. The oceans absorb excess anthropogenic carbon dioxide (CO2) causing decline in ocean pH, a process known as ocean acidification. Many marine organisms are specifically affected by ocean warming, freshening and acidification. Due to the sensitivity of Antarctica to global warming, using biomarkers is the best way for scientists to predict more accurately future climate change and provide useful information or ecological risk assessments. The 70-kilodalton (kDa) heat shock protein (HSP70) chaperones have been used as biomarkers of stress in temperate and tropical environments. The induction of the HSP70 genes (Hsp70) that alter intracellular proteins in living organisms is a signal triggered by environmental temperature changes. Induction of Hsp70 has been observed both in eukaryotes and in prokaryotes as response to environmental stressors including increased and decreased temperature, salinity, pH and the combined effects of changes in temperature, acidification and salinity stress. Generally, HSP70s play critical roles in numerous complex processes of metabolism; their synthesis can usually be increased or decreased during stressful conditions. However, there is a question as to whether HSP70s may serve as excellent biomarkers in the Antarctic considering the long residence time of Antarctic organisms in a cold polar environment which appears to have greatly modified the response of heat responding transcriptional systems. This review provides insight into the vital roles of HSP70 that make them ideal candidates as biomarkers for identifying resistance and resilience in response to abiotic stressors associated with climate change, which are the effects of ocean warming, freshening and acidification in Antarctic organisms.

Marine heatwaves and upwelling shape stress responses in a keystone predator

“…These interactions between HIF1a and HSPs could explain the cross-stress tolerance between heat and hypoxia [77][78][79]. HSPs have also been shown to play an essential role in the response of marine species to acidification (as reviewed by Yusof et al [80]). Therefore, the expression of transcription factors activating HSP genes and, thus, upregulation of HSPs during heatwaves could have also been beneficial for the performance of A. rubens in response to the applied upwelling event.…”

The genetic basis of adaptation to copper pollution in Drosophila melanogaster

“…The presence of 9 SNPs within three heat shock proteins belonging to the highly conserved Hsp70 family of chaperone proteins contributed to enrichment of these GO categories ( Gupta et al, 2010 ): Hsc70-3 , Hsc70-4 , and Hsc70-5 ( The UniProt Consortium et al, 2021 ) ( Figure 6 , Supplementary Table S1 ). Heat shock proteins respond to protein damage caused by oxidative stress following exposure to a diverse set of environmental stressors ( Feder and Hofmann, 1999 ; reviewed in Gupta et al, 2010 ), and the related gene Hsp70 has been linked to response to heavy metal stress in bacteria, plants, nematodes, and fish ( Williams et al, 1996 ; Arts et al, 2004 ; Roh et al, 2006 ; reviewed in Gupta et al, 2010 ; Cui et al, 2013 ; Cui et al, 2019 ; Zuily et al, 2022 ) prompting its assessment for use as a bioindicator of pollution, environmental contamination, and climate change ( Pyza et al, 1997 ; Mukhopadhyay et al, 2003 ; Arts et al, 2004 ; Roh et al, 2006 ; Yusof et al, 2022 ). We recently reported an increase in expression of Hsc70-3 and Hsc70-5 in adult D. melanogaster females from the DSPR in response to copper stress ( Everman et al, 2021 ).…”

Toxicological effects of cadmium on deep-sea mussel Gigantidas platifrons revealed by a combined proteomic and metabolomic approach

“…Expression of seven stress-related proteins belonging to the class of heat shock protein 70 (HSP70) family were significantly altered in deep-sea mussel gills of both Cdexposure groups. HSP70 is a group of highly conserved and abundant proteins that help organisms deal with abiotic stressors (heat shock, salinity change, acidification and contaminants) by refolding, sorting, translocating, and degrading deformed proteins, as well as being cochaperones and regulating the biologically active form of other proteins (Kim and Schöffl, 2002;Chaudhary et al, 2019;Yusof et al, 2022). A field investigation of deep-sea mussel Bathymodiolus azoricus from Atlantic hydrothermal vents confirmed that that this species could express and induce a mixture of constitutive heat-shock protein isoforms, ranging from 64 and 76 kDa, enabling it to survive despite toxic vent fluids (Pruski and Dixon, 2007).…”