Time-dependent expression of heat shock proteins 70 and 90 in tissues of the anoxic western painted turtle

Abstract

Expression of the constitutive Hsp73, inducible Hsp72 and Hsp90 was investigated in brain, heart, liver and skeletal muscle of the anoxia-tolerant western painted turtle Chrysemys picta bellii in response to 2, 6, 12, 18, 24 and 30·h forced dives and following 1·h recovery from 12, 24 and 30·h forced dives at 17°C. During a dive, expression of all three Hsps examined remained at control levels for at least 12·h in all tissues examined except the liver, where Hsp72 showed a decrease at 12·h, reaching a significant threefold decrease by 24·h. Brain and liver Hsp73, 72 and 90 expression increased two-to threefold at 18, 24 and 30·h. Heart and muscle Hsp73 and heart Hsp90 expression remained at normoxic levels throughout the entire dive, while heart and muscle Hsp72 and muscle Hsp90 increased two-to fourfold at 24 and 30·h. Following reoxygenation, Hsp expression increased in all tissues examined. These data indicate that increased Hsp expression is not critical in the early adaptation to anoxic survival and that short-term anoxia is probably not a stress for species adapted to survive long periods without oxygen. However, the late upregulation of heat shock proteins during anoxia suggests that stress proteins play a role in promoting long-term anoxia tolerance.

Tribute to P. L. Lutz: putting life on `pause' – molecular regulation of hypometabolism

“…These were HSP70-1A (the inducible form, also known as Hsp72), HSP70-9B (also known as mortalin-2 or Grp75), HSP40 (also known as DnaJ or HSJ1), and ␣B-crystallin (Storey, 2007). Elevated levels of Hsp72 protein have been reported previously as a response to anoxia in turtle brain and other organs (Prentice et al, 2004;Ramaglia and Buck, 2004). HSP40 is the co-chaperone of HSP70 that acts as a 'holdase' in partnership with the ATPdependent HSP70 'foldase' (Winter and Jakob, 2004), so it is not surprising that they are co-ordinately expressed under anoxia.…”

Growth hormone transgenesis and polyploidy increase metabolic rate, alter the cardiorespiratory response and influence HSP expression to acute hypoxia in Atlantic salmon (Salmo salar) yolk-sac alevins

“…Likewise, the air breathing mudminnow, Umbra limi, responded to hypoxia and 6 h of air exposure with significant increases in HSP70 and HSP90 in liver tissue (Currie et al, 2010). In the anoxia-tolerant western painted turtle, long-term but not short-term anoxia led to an induction of HSPs (constitutive HSP73, inducible HSP72 and HSP90) in several tissues (Ramaglia and Buck, 2004). Hypoxic submergence also resulted in elevated levels of HSP70 in the hearts of the hypoxiatolerant common frog, Rana temporaria (Currie and Boutilier, 2001).…”

Heat shock proteins and hypometabolism: adaptive strategy for proteome preservation

“…[55][56][57][58] Figure 2 summarizes HSP responses to 20 hours of anoxic submergence and 5 hours of aerobic recovery in the white muscle of red-eared slider turtles (Trachemys scripta elegans). Anoxia induced a strong 2-to 3-fold increase in protein levels of Hsp25, Hsp40, Hsp70, Hsc70, and Hsp90 in muscle.…”

“…Hsp70, Hsc70, and Hsp90 were unaffected over the early hours of a forced dive in painted turtles tissues but generally rose 2-to 3-fold after 12-30 hours, indicating that chaperones become more important when anoxia exposure is prolonged. 56 It is well known that turtle diving has a two-phase pattern. Initially, animals go through a hypoxia transition period during which metabolic rate stays near normal until blood oxygen falls to a critical minimum pO 2 .…”