Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: UNIPROT:P21817 (
RyR1
)
1,154
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
:
Intracellular calcium (Ca
2+
) homeostasis plays a vital role in the preservation of skeletal muscle. In view of the well-maintained skeletal muscle found in Daurian ground squirrels (
Spermophilus dauricus
) during hibernation, we hypothesized that hibernators possess unique strategies of intracellular Ca
2+
homeostasis. Here, cytoplasmic, sarcoplasmic reticulum (SR), and mitochondrial Ca
2+
levels, as well as the potential Ca
2+
regulatory mechanisms, were investigated in skeletal muscle fibers of Daurian ground squirrels at different stages of hibernation. The results showed that cytoplasmic Ca
2+
levels increased in the skeletal muscle fibers during late torpor (LT) and inter-bout arousal (IBA), and partially recovered when the animals re-entered torpor (early torpor, ET). Furthermore, compared with levels in the summer active or pre-hibernation state, the activity and protein expression levels of six major Ca
2+
channels/proteins were up-regulated during hibernation, including the store-operated Ca
2+
entry (SOCE),
ryanodine receptor 1
(
RyR1
),
leucine zipper-EF-hand containing transmembrane protein 1
(
LETM1
), SR Ca
2+
ATPase 1 (SERCA1), mitochondrial calcium uniporter complex (MCU complex), and calmodulin (CALM). Among these, the increased extracellular Ca
2+
influx mediated by SOCE, SR Ca
2+
release mediated by
RyR1
, and mitochondrial Ca
2+
extrusion mediated by
LETM1
may be triggers for the periodic elevation in cytoplasmic Ca
2+
levels observed during hibernation. Furthermore, the increased SR Ca
2+
uptake through SERCA1, mitochondrial Ca
2+
uptake induced by MCU, and elevated free Ca
2+
binding capacity mediated by CALM may be vital strategies in hibernating ground squirrels to attenuate cytoplasmic Ca
2+
levels and restore Ca
2+
homeostasis during hibernation. Compared with that in LT or IBA, the decreased extracellular Ca
2+
influx mediated by SOCE and elevated mitochondrial Ca
2+
uptake induced by MCU may be important mechanisms for the partial cytoplasmic Ca
2+
recovery in ET. Overall, under extreme conditions, hibernating ground squirrels still possess the ability to maintain intracellular Ca
2+
homeostasis.
...
PMID:Priority Strategy of Intracellular Ca
2+
Homeostasis in Skeletal Muscle Fibers During the Multiple Stresses of Hibernation. 3187 83
