Enzymes of Adenylate Metabolism and Their Role in Hibernation of the White-Tailed Prairie Dog, Cynomys leucurus

English, Tamara E.; Storey, Kenneth B.

doi:10.1006/abbi.1999.1686

Cited by 40 publications

(45 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although the observed decrease of P-CFL2 in the hibernator's hearts (Fig. 7) could indicate that ATP availability is limited during the entrance, torpid, and early arousal periods, others have shown that tissue ATP levels (43,58,75) and/or energy charge (10,19) are maintained throughout hibernation. Furthermore, the hibernator's heart is able to maintain ion homeostasis and contractility in the cold, therefore it is unlikely that ATP is depleted in the heart during these states.…”

Section: Cfl2mentioning

confidence: 94%

Multistate proteomics analysis reveals novel strategies used by a hibernator to precondition the heart and conserve ATP for winter heterothermy

Grabek

Karimpour-Fard

Epperson³

et al. 2011

Physiological Genomics

View full text Add to dashboard Cite

SL. Multistate proteomics analysis reveals novel strategies used by a hibernator to precondition the heart and conserve ATP for winter heterothermy. Physiol Genomics 43: 1263-1275. First published September 13, 2011 doi:10.1152/physiolgenomics.00125.2011.-The hibernator's heart functions continuously and avoids damage across the wide temperature range of winter heterothermy. To define the molecular basis of this phenotype, we quantified proteomic changes in the 13-lined ground squirrel heart among eight distinct physiological states encompassing the hibernator's year. Unsupervised clustering revealed a prominent seasonal separation between the summer homeotherms and winter heterotherms, whereas within-season state separation was limited. Further, animals torpid in the fall were intermediate to summer and winter, consistent with the transitional nature of this phase. A seasonal analysis revealed that the relative abundances of protein spots were mainly winter-increased. The winter-elevated proteins were involved in fatty acid catabolism and protein folding, whereas the winter-depleted proteins included those that degrade branched-chain amino acids. To identify further statedependent changes, protein spots were re-evaluated with respect to specific physiological state, confirming the predominance of seasonal differences. Additionally, chaperone and heat shock proteins increased in winter, including HSPA4, HSPB6, and HSP90AB1, which have known roles in protecting against ischemia-reperfusion injury and apoptosis. The most significant and greatest fold change observed was a disappearance of phospho-cofilin 2 at low body temperature, likely a strategy to preserve ATP. The robust summer-to-winter seasonal proteomic shift implies that a winter-protected state is orchestrated before prolonged torpor ensues. Additionally, the general preservation of the proteome during winter hibernation and an increase of stress response proteins, together with dephosphorylation of cofilin 2, highlight the importance of ATP-conserving mechanisms for winter cardioprotection. 2D DiGE; CFL2; hibernating; Ictidomys (spermophilus) tridecemlineatus; mass spectrometry HIBERNATION IN MAMMALS IS characterized by dramatic, but reversible, reductions in body temperature (T b ) and metabolic rate. During this torpid phase, respiration and heart rate also decline to 1-4% of their euthermic values (for review, see Ref. 11). Torpor bouts are punctuated by interbout arousals (54), when physiological rates are restored to or even surpass euthermic levels (11). For circannual hibernators such as 13-lined ground squirrels, Ictidomys tridecemlineatus, the ability to orchestrate reversible metabolic depression exists only in winter (reviewed in Ref. 38). This heterothermic winter phenotype contrasts markedly with summer, when animals remain homeotherms. A "two-switch" mechanism in which animals first switch from summer homeothermy to a state that is permissive for winter heterothermy (switch 1), and then cycle between periods of torpor and arousal in winte...

show abstract

Section: Cfl2mentioning

confidence: 94%

Multistate proteomics analysis reveals novel strategies used by a hibernator to precondition the heart and conserve ATP for winter heterothermy

Grabek

Karimpour-Fard

Epperson³

et al. 2011

Physiological Genomics

View full text Add to dashboard Cite

show abstract

“…274), golden-mantled ground squirrels (183) and white-tailed prairie dogs (Cynomus leucurus; ref. 91), ATP concentrations may decline by more than 50% in hibernation, but in some cases, such declines are not matched by corresponding increases of ADP or AMP (183,274). Instead, there is a decrease in total tissue adenylate concentrations, presumably by deamination of adenosine.…”

Section: Does Energy Metabolism Remain Balanced In Temporal Heterothementioning

confidence: 96%

Metabolic Flexibility: Hibernation, Torpor, and Estivation

Staples

2016

Comprehensive Physiology

136

116

View full text Add to dashboard Cite

Many environmental conditions can constrain the ability of animals to obtain sufficient food energy, or transform that food energy into useful chemical forms. To survive extended periods under such conditions animals must suppress metabolic rate to conserve energy, water, or oxygen. Amongst small endotherms, this metabolic suppression is accompanied by and, in some cases, facilitated by a decrease in core body temperature-hibernation or daily torpor-though significant metabolic suppression can be achieved even with only modest cooling. Within some ectotherms, winter metabolic suppression exceeds the passive effects of cooling. During dry seasons, estivating ectotherms can reduce metabolism without changes in body temperature, conserving energy reserves, and reducing gas exchange and its inevitable loss of water vapor. This overview explores the similarities and differences of metabolic suppression among these states within adult animals (excluding developmental diapause), and integrates levels of organization from the whole animal to the genome, where possible. Several similarities among these states are highlighted, including patterns and regulation of metabolic balance, fuel use, and mitochondrial metabolism. Differences among models are also apparent, particularly in whether the metabolic suppression is intrinsic to the tissue or depends on the whole-animal response. While in these hypometabolic states, tissues from many animals are tolerant of hypoxia/anoxia, ischemia/reperfusion, and disuse. These natural models may, therefore, serve as valuable and instructive models for biomedical research.

show abstract

“…The frog Rana temporaria survives several months in hypoxic water with no fall in skeletal muscle ATP and no rise in AMP concentration (Donohoe et al 1998). In skeletal muscles of the hibernating ground squirrel, Spermophilus lateralis (MacDonald and Storey 1999), or of the hibernating white-tailed prairie dog, Cynomys leucurus (English and Storey 2000), although total adenine nucleotide levels fell, there was no change in AEC or in AMP concentration. Also, liver ATP and ADP levels did not change in different stages of hibernation bouts in S. lateralis (Staples and Hochachka 1997).…”

Section: Evolution Of Ampkmentioning

confidence: 97%

Role of AMP-activated protein kinase in metabolic depression in animals

Rider

2015

J Comp Physiol B

View full text Add to dashboard Cite

AMP-activated protein kinase (AMPK) is a highly conserved eukaryotic protein serine/threonine kinase that controls cellular and whole body energy homoeostasis. AMPK is activated during energy stress by a rise in AMP:ATP ratio and maintains energy balance by phosphorylating targets to switch on catabolic ATP-generating pathways, while at the same time switching off anabolic ATP-consuming processes. Metabolic depression is a strategy used by many animals to survive environmental stress and has been extensively studied across phylogeny by comparative biochemists and physiologists, but the role of AMPK has only recently been addressed. This review first deals with the evolution of AMPK in eukaryotes (excluding plants and fungi) and its regulation. Changes in adenine nucleotides and AMPK activation are described in animals during environmental energy stress, before considering the involvement of AMPK in controlling β-oxidation, fatty acid synthesis, triacylglycerol mobilization and protein synthesis. Lastly, strategies are presented to validate the role of AMPK in mediating metabolic depression by phosphorylating downstream targets.

show abstract

Enzymes of Adenylate Metabolism and Their Role in Hibernation of the White-Tailed Prairie Dog, Cynomys leucurus

Cited by 40 publications

References 25 publications

Multistate proteomics analysis reveals novel strategies used by a hibernator to precondition the heart and conserve ATP for winter heterothermy

Multistate proteomics analysis reveals novel strategies used by a hibernator to precondition the heart and conserve ATP for winter heterothermy

Metabolic Flexibility: Hibernation, Torpor, and Estivation

Role of AMP-activated protein kinase in metabolic depression in animals

Contact Info

Product

Resources

About