The ryanodine receptor/calcium channel genes are widely and differentially expressed in murine brain and peripheral tissues.

Abstract

Abstract. Ryanodine receptors (RyRs) are intracellular calcium release channels that participate in controlling cytosolic calcium levels. At variance with the probably ubiquitous inositol 1,4,5-trisphosphate-operated calcium channels (1,4,5-trisphosphate receptors), RyRs have been mainly regarded as the calcium release channels controlling skeletal and cardiac muscle contraction. Increasing evidence has recently suggested that RyRs may be more widely expressed, but this has never been extensively examined. Therefore, we cloned three cDNAs corresponding to murine RyR homologues to carry a comprehensive analysis of their expression in murine tissues. Here, we report that the three genes are expressed in almost all tissues analyzed, where tissue-specific patterns of expression were observed. In the uterus and vas deferens, expression of RyR3 was localized to the smooth muscle component of these organs. In the testis, expression of RyR1 and RyR3 was detected in germ cells. RyR mRNAs were also detected in in vitro-cultured cell lines. RyR1, RyR2, and RyR3 mRNA were detected in the cerebrum and in the cerebellum. In situ analysis revealed a cell type-specific pattern of expression in the different regions of the central nervous system. The differential expression of the three ryanodine receptor genes in the central nervous system was also confirmed using specific antibodies against the respective proteins. This widespread pattern of expression suggests that RyRs may participate in the regulation of intraceUular calcium homeostasis in a range of cells wider than previously recognized.

Type 1 and type 3 ryanodine receptors are selectively involved in muscarinic antinociception in mice: An antisense study

“…RyR1 was present in cerebellum, hippocampus and striatum, but it was not detected in mouse cortex. These results are in agreement with previous studies in murine brain (Giannini et al, 1995).…”

“…RyR2 represents the predominant isoform in the CNS found in widespread brain regions (McPherson and Campbell, 1993;Giannini et al, 1995). Some studies indicate that RyR2, similarly to RyR3, is involved in the modulation of memory processes.…”

cADP-ribose potentiates cytosolic Ca2+ elevation and Ca2+ entry via L-type voltage-activated Ca2+ channels in NG108-15 neuronal cells

“…Chavis et al have shown a similar signal in cerebellar granule cells [12], where RyRs activated by type-1 metabotropic glutamate receptors increase VACC activity. Since it has been reported that cerebellar granule cells possess RyR-2 and RyR-3 [5,6], the retrograde signal from RyR-2 or RyR-3 may target the L-type VACCs. Our results support and extend this novel idea that L-type VACCs and RyRs are functionally coupled, and we provide the first evidence for the involvement of cADPR in this coupling, as shown in Scheme 1.…”

“…cADP-ribose (cADPR) [3] has been suggested to be a second messenger or endogenous modulator for CICR [4], acting on specific subtypes of RyRs. The cardiac and brain isoforms of type-2 RyRs (RyR-2) and brain isoforms of type-3 RyRs (RyR-3) [5,6] are activated by cADPR [7,8], but the skeletal-muscle isoforms of type-1 RyRs (RyR-1) are not [8,9]. Whereas RyR-1 is coupled to L-type voltage-activated Ca# + channels (VACCs) through proteinprotein interactions [10], such direct coupling has not been shown in RyR-2 and RyR-3.…”

Similar Ca2+ dependences of [3H]ryanodine binding to α‐ and β‐ryanodine receptors purified from bullfrog skeletal muscle in an isotonic medium

“…Recently, mRNA for Ryr3 has been detected in mammalian skeletal muscles [26,27]. However, the amount of the isoform is considered to be very minute, because only a single band corresponding to Ryrl is visible on SDS-PAGE of SR vesicles from these muscles in contrast to two bands which are observed in SR vesicles from bullfrog skeletal muscle.…”