caa a22 4500 605514097 CHVBK 20210128100703.0 cr unu---uuuuu 210128e20151001xx s 000 0 eng 10.1007/s00360-015-0916-6 doi (NATIONALLICENCE)springer-10.1007/s00360-015-0916-6 Chaperone roles for TMAO and HSP70 during hyposmotic stress in the spiny dogfish shark ( Squalus acanthias ) [Elektronische Daten] [Robyn MacLellan, Louise Tunnah, David Barnett, Patricia Wright, Tyson MacCormack, Suzanne Currie] Salinity decreases are experienced by many marine elasmobranchs. To understand how these fishes cope with hyposmotic stress on a cellular level, we used the spiny dogfish shark (Squalus acanthias) as a model to test whether a reciprocal relationship exists between the cell's two primary protein protection mechanisms, the chemical (e.g., trimethylamine oxide, TMAO) and molecular (e.g., heat shock protein 70, HSP70) chaperone systems. This relationship is interesting given that many elasmobranchs are expected to gain water and lose osmolytes, chemical chaperones, and ions as they osmoconform to new, lowered salinity. Dogfish were cannulated for repeated blood sampling and exposed to 70% seawater (SW) for 48h. These hyposmotic conditions had no effect on red blood cell (RBC) and white muscle TMAO concentrations, and did not result in HSP70 induction or signs of protein damage (i.e., increased ubiquitin), suggesting that TMAO levels were sufficiently protective in these tissues. However, in the gill, we observed a significant decrease in TMAO concentration and a significant induction of HSP70 as well as signs of protein damage. In the face of this cellular stress response, gill Na+/K+-ATPase (NKA) activity significantly increased during hyposmotic conditions, as expected. We suggest that this functional preservation in the gill is partly the result of HSP70 induction with lowered salinity. We conclude a reciprocal relationship between TMAO and HSP70 in the gills of dogfish as a result of in vivo hyposmotic stress. When osmotically induced protein damage surpasses the protective capacity of remaining TMAO, HSP70 is induced to preserve tissue and organismal function. Springer-Verlag Berlin Heidelberg, 2015 Heat shock proteins nationallicence Trimethylamine oxide nationallicence Elasmobranch nationallicence Gill nationallicence Chemical chaperone nationallicence Ubiquitin nationallicence MacLellan Robyn Department of Biochemistry, Mount Allison University, Sackville, NB, Canada aut Tunnah Louise Department of Biology, Mount Allison University, E4L 1G7, Sackville, NB, Canada aut Barnett David Atlantic Cancer Research Institute, Moncton, NB, Canada aut Wright Patricia Department of Integrative Biology, University of Guelph, Guelph, ON, Canada aut MacCormack Tyson Department of Biochemistry, Mount Allison University, Sackville, NB, Canada aut Currie Suzanne Department of Biology, Mount Allison University, E4L 1G7, Sackville, NB, Canada aut Journal of Comparative Physiology B Springer Berlin Heidelberg 185/7(2015-10-01), 729-740 0174-1578 185:7<729 2015 185 360 https://doi.org/10.1007/s00360-015-0916-6 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00360-015-0916-6 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- MacLellan Robyn Department of Biochemistry, Mount Allison University, Sackville, NB, Canada aut NATIONALLICENCE 700 1- Tunnah Louise Department of Biology, Mount Allison University, E4L 1G7, Sackville, NB, Canada aut NATIONALLICENCE 700 1- Barnett David Atlantic Cancer Research Institute, Moncton, NB, Canada aut NATIONALLICENCE 700 1- Wright Patricia Department of Integrative Biology, University of Guelph, Guelph, ON, Canada aut NATIONALLICENCE 700 1- MacCormack Tyson Department of Biochemistry, Mount Allison University, Sackville, NB, Canada aut NATIONALLICENCE 700 1- Currie Suzanne Department of Biology, Mount Allison University, E4L 1G7, Sackville, NB, Canada aut NATIONALLICENCE 773 0- Journal of Comparative Physiology B Springer Berlin Heidelberg 185/7(2015-10-01), 729-740 0174-1578 185:7<729 2015 185 360