Full length ryanodine receptor subtype 3 encodes spontaneous calcium oscillations in native duodenal smooth muscle cells
Cell Calcium. 2008-08-01; 44(2): 180-189
DOI: 10.1016/j.ceca.2007.11.009
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1. Cell Calcium. 2008 Aug;44(2):180-9. doi: 10.1016/j.ceca.2007.11.009. Epub 2008
Jan 18.
Full length ryanodine receptor subtype 3 encodes spontaneous calcium oscillations
in native duodenal smooth muscle cells.
Dabertrand F(1), Mironneau J, Macrez N, Morel JL.
Author information:
(1)Centre de Neurosciences Intégratives et Cognitives, CNRS UMR5228, Universités
de Bordeaux, avenue des facultés, 33405 Talence, France.
Two isoforms of the ryanodine receptor subtype 3 (RYR3) have been described in
smooth muscle. The RYR3 short isoform (RYR3S) negatively regulates the
calcium-induced calcium release mechanism encoded by the RYR2, whereas the role
of the full length isoform of RYR3 (RYR3L) was still unclear. Here, we describe
RYR-dependent spontaneous Ca(2+) oscillations measured in 10% of native duodenum
myocytes. We investigated the role of RYR3 isoforms in these spontaneous Ca(2+)
signals. Inhibition of RYR3S expression by antisense oligonucleotides revealed
that both RYR2 and RYR3L were able to propagate spontaneous Ca(2+) waves that
were distinguishable by frequency analysis. When RYR3L expression was inhibited,
the spontaneous Ca(2+) oscillations were never observed, indicating that RYR3S
inhibited the function of RYR2. RYR2 expression inhibition led to Ca(2+)
oscillations identical to those observed in control cells suggesting that RYR3S
did not functionally interact with RYR3L. The presence and frequency of
RYR3L-dependent Ca(2+) oscillations were dependent on sarcoplasmic reticulum
Ca(2+) content as revealed by long-term changes of the extracellular Ca(2+)
concentration. Our study shows that, in native duodenal myocytes, the spontaneous
Ca(2+) waves are encoded by the RYR3L alone, which activity is regulated by
sarcoplasmic reticulum Ca(2+) loading.
DOI: 10.1016/j.ceca.2007.11.009
PMID: 18207571 [Indexed for MEDLINE]