Abstract
To better understand the role of the transient expression of ryanodine receptor (RyR) type 3 (RyR3) on Ca2+ homeostasis during the development of skeletal muscle, we have analyzed the effect of expression levels of RyR3 and RyR1 on the overall physiology of cultured myotubes and muscle fibers. Dyspedic myotubes were infected with RyR1 or RyR3 containing virions at 0.2, 0.4, 1.0, and 4.0 moieties of infection (MOI), and analysis of their pattern of expression, caffeine sensitivity, and resting free Ca2+ concentration ([Ca2+]r) was performed. Although increased MOI resulted in increased expression of each receptor isoform, it did not significantly affect the immunopattern of RyRs or the expression levels of calsequestrin, triadin, or FKBP-12. Interestingly, myotubes expressing RyR3 always had significantly higher [Ca2+]r and lower caffeine EC50 than did cells expressing RyR1. Although some of the increased sensitivity of RyR3 to caffeine could be attributed to the higher [Ca 2+]r in RyR3-expressing cells, studies of [ 3H]ryanodine binding demonstrated intrinsic differences in caffeine sensitivity between RyR1 and RyR3. Tibialis anterior (TA) muscle fibers at different stages of postnatal development exhibited a transient increase in [Ca2+]r coordinately with their level of RyR3 expression. Similarly, adult soleus fibers, which also express RyR3, had higher [Ca 2+]r than did adult TA fibers, which exclusively express RyR1. These data show that in skeletal muscle, RyR3 increases [Ca 2+]r more than RyR1 does at any expression level. These data suggest that the coexpression of RyR1 and RyR3 at different levels may constitute a novel mechanism by which to regulate [Ca2+]r in skeletal muscle.
| Original language | English (US) |
|---|---|
| Journal | American Journal of Physiology - Cell Physiology |
| Volume | 288 |
| Issue number | 3 57-3 |
| DOIs | |
| State | Published - Mar 2005 |
| Externally published | Yes |
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Keywords
- Calcium release
- Muscle fibers
- Ryanodine binding
- Ryanodine receptor
ASJC Scopus subject areas
- Clinical Biochemistry
- Cell Biology
- Physiology
Cite this
Expression levels of RyR1 and RyR3 control resting free Ca2+ in skeletal muscle. / Perez, Claudio F.; López, José R.; Allen, Paul D.
In: American Journal of Physiology - Cell Physiology, Vol. 288, No. 3 57-3, 03.2005.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Expression levels of RyR1 and RyR3 control resting free Ca2+ in skeletal muscle
AU - Perez, Claudio F.
AU - López, José R.
AU - Allen, Paul D.
PY - 2005/3
Y1 - 2005/3
N2 - To better understand the role of the transient expression of ryanodine receptor (RyR) type 3 (RyR3) on Ca2+ homeostasis during the development of skeletal muscle, we have analyzed the effect of expression levels of RyR3 and RyR1 on the overall physiology of cultured myotubes and muscle fibers. Dyspedic myotubes were infected with RyR1 or RyR3 containing virions at 0.2, 0.4, 1.0, and 4.0 moieties of infection (MOI), and analysis of their pattern of expression, caffeine sensitivity, and resting free Ca2+ concentration ([Ca2+]r) was performed. Although increased MOI resulted in increased expression of each receptor isoform, it did not significantly affect the immunopattern of RyRs or the expression levels of calsequestrin, triadin, or FKBP-12. Interestingly, myotubes expressing RyR3 always had significantly higher [Ca2+]r and lower caffeine EC50 than did cells expressing RyR1. Although some of the increased sensitivity of RyR3 to caffeine could be attributed to the higher [Ca 2+]r in RyR3-expressing cells, studies of [ 3H]ryanodine binding demonstrated intrinsic differences in caffeine sensitivity between RyR1 and RyR3. Tibialis anterior (TA) muscle fibers at different stages of postnatal development exhibited a transient increase in [Ca2+]r coordinately with their level of RyR3 expression. Similarly, adult soleus fibers, which also express RyR3, had higher [Ca 2+]r than did adult TA fibers, which exclusively express RyR1. These data show that in skeletal muscle, RyR3 increases [Ca 2+]r more than RyR1 does at any expression level. These data suggest that the coexpression of RyR1 and RyR3 at different levels may constitute a novel mechanism by which to regulate [Ca2+]r in skeletal muscle.
AB - To better understand the role of the transient expression of ryanodine receptor (RyR) type 3 (RyR3) on Ca2+ homeostasis during the development of skeletal muscle, we have analyzed the effect of expression levels of RyR3 and RyR1 on the overall physiology of cultured myotubes and muscle fibers. Dyspedic myotubes were infected with RyR1 or RyR3 containing virions at 0.2, 0.4, 1.0, and 4.0 moieties of infection (MOI), and analysis of their pattern of expression, caffeine sensitivity, and resting free Ca2+ concentration ([Ca2+]r) was performed. Although increased MOI resulted in increased expression of each receptor isoform, it did not significantly affect the immunopattern of RyRs or the expression levels of calsequestrin, triadin, or FKBP-12. Interestingly, myotubes expressing RyR3 always had significantly higher [Ca2+]r and lower caffeine EC50 than did cells expressing RyR1. Although some of the increased sensitivity of RyR3 to caffeine could be attributed to the higher [Ca 2+]r in RyR3-expressing cells, studies of [ 3H]ryanodine binding demonstrated intrinsic differences in caffeine sensitivity between RyR1 and RyR3. Tibialis anterior (TA) muscle fibers at different stages of postnatal development exhibited a transient increase in [Ca2+]r coordinately with their level of RyR3 expression. Similarly, adult soleus fibers, which also express RyR3, had higher [Ca 2+]r than did adult TA fibers, which exclusively express RyR1. These data show that in skeletal muscle, RyR3 increases [Ca 2+]r more than RyR1 does at any expression level. These data suggest that the coexpression of RyR1 and RyR3 at different levels may constitute a novel mechanism by which to regulate [Ca2+]r in skeletal muscle.
KW - Calcium release
KW - Muscle fibers
KW - Ryanodine binding
KW - Ryanodine receptor
UR - http://www.scopus.com/inward/record.url?scp=13644270257&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=13644270257&partnerID=8YFLogxK
U2 - 10.1152/ajpcell.00407.2004
DO - 10.1152/ajpcell.00407.2004
M3 - Article
C2 - 15548569
AN - SCOPUS:13644270257
VL - 288
JO - American Journal of Physiology - Renal Fluid and Electrolyte Physiology
JF - American Journal of Physiology - Renal Fluid and Electrolyte Physiology
SN - 1931-857X
IS - 3 57-3
ER -