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Biological Research

versión impresa ISSN 0716-9760

Biol. Res. v.35 n.2 Santiago  2002 

Biol Res 35:195-202, 2002

IP3 dependent Ca2+ signals in muscle cells are involved in
regulation of gene expression.


Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 6530499, casilla 70005, Santiago , Chile.


Potassium depolarization of cultured muscle cells was employed to study cellular responses linked to calcium signaling. Events occurring after depolarization include i) A transient increase of the IP3 mass (2-10s); ii) A slow calcium transient (5 to 25s) that propagates as a low concentration wave along the myotube showing a distinct calcium transient at the level of cell nuclei. Due to the presence of IP3 receptors both in the SR (A-band region) and in the nuclear envelope, these two events appear to be related; iii) Phosphorylation of mitogen activated kinases (ERK 1/2) and of the transcription factor CREB (30 s-10 min), as well as expression of the early genes c-fos, c-jun and egr-1 mRNA (5-15 min). Several independent pieces of evidence, including results obtained using inhibitors specific for individual steps, allowed us to connect these in a sequential manner. As the same type of signaling cascade can be triggered by oxidants, neurotransmitters and hormones, the ensemble of results allows us to propose a general model to describe signaling events that link membrane stimulation to regulation of gene transcription in skeletal muscle cells.

Key terms: Excitation-transcription; inositol trisphosphate; mitogen-activated kinases; CREB; early genes; dihydropyridine receptors.


Increased use, decreased use and injury are known to induce different forms of muscle adaptation. However, the cellular mechanisms responsible for these changes remain unknown. Since the process of muscle adaptation is completely dependent on nerve activity and on nerve-muscle interaction, it constitutes a good model to study plasticity and regeneration of excitable cells. Cultured muscle cells allow the study of many functions characteristic of adult muscle, including growth, differentiation, adaptation and contraction.

Between 1981 and 1989, a number of papers were published demonstrating the presence in skeletal muscle membranes of the metabolic machinery needed to produce inositol (1,4,5) trisphosphate (IP3) (Jaimovich, 1991). Indeed, IP3 was capable of releasing calcium from internal stores in ruptured fibers (Rojas and Jaimovich, 1990), but no role for IP3 in excitation-

contraction (E-C) coupling was apparent. To gain insight to this problem, studies in intact cells were necessary, and we choose cultured skeletal muscle (both primary culture and cell lines, some developed in our laboratories) as a model. A series of recent publications, as well as yet unpublished work, suggest a role for IP3 in the regulation of nucleoplasmic calcium, leading to early gene expression in these cells. Most interestingly, dihydropyridine receptors (DHPR) appear again in a role as voltage sensors, now for excitation-transcription coupling.

In multiple types of mammalian cells the level of intracellular Ca2+ controls an enormous number of cell functions, including cell division, secretion, gene expression, cell motility, and muscle contraction (Berridge, 2000). Different qualitative and quantitative aspects of Ca2+ signals, including amplitude, frequency and localization, determine the specificity of cellular responses (see Petersen, 2002). The problem of Ca2+- dependent regulation of gene expression, and thus cellular differentiation, is especially intriguing to the developmental biologist. When one thinks of Ca2+ signals in skeletal muscle, the exquisite control of E-C coupling comes to mind. This involves DHPRs and activation of the ryanodine receptors (RyR), the Ca2+ release channels of the sarcoplasmic reticulum (SR). The complex regulation of RyR activity in skeletal and cardiac skeletal muscle, by Ca2+, Mg2+ and redox state, is discussed elsewhere (Hidalgo et al., 2002).

Assuming Ca2+ is employed as a second messenger to control functions other than those limited to contraction of skeletal muscle, it is likely that both the kinetics of the Ca2+ signals and the subcellular location, as well as the nature of the Ca2+ release channels involved, would be different from those of the channels linked to E-C coupling. In many cells, intracellular increases in Ca2+ are mediated by the IP3 cascade (Berridge, 1993). The activation of various types of receptors in different cells induces the hydrolysis of membrane phosphatidylinositol 4,5-bisphosphate (PIP2) to generate IP3 and diacylglycerol, which are activators of intracellular Ca2+ channels and protein kinase C, respectively. Indeed, skeletal muscle fibers possess the basic molecular machinery that constitutes a functioning IP3 messenger system, including phosphatidylinositol-4-kinase, phosphatidylinositol-4 phosphate-5-kinase (Hidalgo et al., 1986; Carrasco et al., 1988), phospholipase C (Carrasco et al., 1993), inositolphosphate phosphatases (Sanchez et al., 1991), IP3 3-kinase (Carrasco and Figueroa, 1995), and G-proteins (Scherer et al., 1987; Carrasco et al., 1994). Some of these enzyme activities, particularly that of phosphatidylinositol-4 phosphate-5-kinase, have been localized to the transverse tubule (T-tubule) system (Carrasco et al., 1988). In addition, IP3-sensitive Ca2+ channels have been found in the SR (Volpe et al., 1986; Suarez-Isla et al., 1988). Thus, depolarization of the T-tubule system could lead to IP3 production and release of internal Ca2+ in addition to Ca2+ release through the RyRs.

Slow calcium signals in skeletal muscle cells.

In skeletal muscle cells, Ca2+ release from internal stores may follow more than one set of kinetics and may have more than one function. Ca2+ waves, unrelated to Ca2+ spikes involved in E-C coupling, have been reported in both chicken and rodent myotubes (Flucher and Andrews, 1993; Powell et al., 1996). We have shown that the complex Ca2+ release response, induced by elevated potassium, involves two components with different kinetics (Jaimovich and Rojas, 1994; Jaimovich et al., 2000). One is a fast Ca2+ transient, known to be associated with the RyR and E-C coupling. The other a slower transient with as yet poorly defined causes and unknown functions. DHPRs appear to be the membrane voltage sensors for the slow calcium signal, since 10 µM nifedipine completely blocked the slow Ca2+ transient after K+ depolarization but only partially reduced the fast Ca2+ signal. In dysgenic myotubes, which do not express the alpha 1 subunit of the DHPR (GLT cell line), no calcium signal after depolarization was detectable (Araya et al., manuscript in preparation). After transfection of the alpha 1 subunit, K+ depolarization induced slow calcium transients that were similar to those present in normal C2C12 and NLT cell lines.

Also, depolarization of cultured muscle leads to an increase in IP3 mass (Jaimovich et al., 2000). Recently, presence of the IP3R has been shown both biochemically (Liberona et al., 1998) and immunocytologically (Jaimovich et al., 2000; Powell et al., 2001) in normal and diseased muscle, further suggesting a role for IP3 signals. Biochemical localization of IP3Rs to isolated nuclei of developing muscle further implicates the IP3 cascade in nuclear signaling events (Liberona et al., 1998). To understand this possible role of IP3Rs in the propagation of such Ca2+ transients and perhaps in the modulation of growth and development of skeletal muscle, we investigated the expression and subcellular localization of these receptors in cultured muscle. Furthermore, we explored the link between IP3Rs and slow Ca2+ signals, and sought possible downstream targets for these signals in muscle cells.

Expression of mRNA and proteins of the IP3R isotypes

At the mRNA and protein levels, three IP3R isoforms have been previously demonstrated to be present in different proportions in a number of rodent cell lines (Newton et al., 1994; Wojcikiewicz, 1995; De Smedt et al., 1997). In particular, the study of mRNA expression performed by De Smedt et al., (1997) has shown that in three mouse skeletal cell lines, including C2C12 cells, IP3R type 3 is clearly the most abundant transcript. The proportion of types 1 and 2 vary in these cell lines, but there was a tendency for type 2 to increase and for type 3 to decrease as differentiation proceeds. Our IP3 binding results (Liberona et al., 1998; Jaimovich et al., 2000) show that at least two isoforms are present in the nuclear region. In addition, these binding studies indicate that a high proportion of the IP3Rs are found in the nuclear fraction in both cell lines and primary cultures. Nuclear localization of specific IP3R isoforms in skeletal muscle has not been described in the literature. To confirm and extend these findings we have looked at the expression (mRNA and protein) and the localization of the IP3R (Powell et al., 2001a,b). Confocal microscopy of cultured mouse muscle, doubly labeled for the IP3R type 1 and proteins of known distribution, reveals that these receptors are localized to the I band of the sarcoplasmic reticulum and shows that the staining for IP3R type 1 is continuous with staining of the nuclear envelope region.

Link between IP3Rs and cytoplasmic Ca2+ transients

The slow calcium signal (monitored as the response to fluo-3) moves through the cytoplasm and seems to trigger even higher Ca2+ concentrations inside nuclei, perhaps by moving from the region of the nuclear envelope to the nucleoplasm. In fact, the slow calcium wave can be envisaged as having two components, a more rapid, diffuse component (slow-rapid) of low fluorescence intensity, that always precedes a localized high fluorescence wave (slow-slow component) that propagates from one nucleus to another.

The role of the IP3Rs in the I-band SR region could be related to the diffuse, low fluorescence intensity, cytosolic component, we see always associated with localized nuclear Ca2+ increases. Since the cell does not contract during either part of the slow wave, this indicates that the overall cytosolic calcium concentration remains below the contraction threshold and that high fluorescence areas must be highly compartmentalized, most probably in the nuclear region (Estrada et al., 2000; Jaimovich et al., 2000). As expected, high concentrations of ryanodine eliminated the initial fast calcium increase associated with contraction, and interestingly it also eliminated the first or slow-rapid cytosolic propagation component as well. However the second slow calcium rise (slow-slow) phase was preserved. This suggests that a ryanodine sensitive calcium pool is involved in propagation of the slowrapid Ca2+ wave through the cytosol. The apparently different intracellular distribution of receptors, RyR in the SR membranes and IP3Rs, at least in some developmental stages, concentrated in membranes associated with the nuclei, points to the presence of two separate calcium release systems (Humbert et al., 1996; Guihard et al., 1997; Liberona et al., 1998; Petersen et al., 1998). We propose that the role for the IP3R is to maintain cytosolic calcium concentrations within the appropriate range in distinct sub-cellular regions and, more specifically, to control nuclear calcium release.

An important finding was that pre-incubation of cells with 2-APB (2-aminoethoxydiphenyl borate) inhibited slow Ca2+ signals (Estrada et al., 2001; Powell et al., 2001). This compound has been shown to be a fairly specific inhibitor of IP3 mediated Ca2+ release. The complete absence of slow Ca2+ waves in the presence of 2-APB suggests that these signals are mediated by IP3Rs. Similar results were obtained using other compounds interfering with the IP3 system, such as the IP3R blocker xestospongin-C, or the PLC inhibitor U-73122 (Estrada et al., 2001). As IP3R channels require both IP3 and Ca2+ for activation, the function of IP3Rs located in the I-band SR region could be to propagate a local Ca2+ wave that would ensure Ca2+ availability in the nuclear region, required for local Ca2+ release and regulation of gene expression (see figure 1), without causing contraction.

Role of RyRs in slow calcium signals

In order to define the role of RyRs, in either component of the slow release process, we compared the calcium signals in muscle cells (1B5) from dyspedic mice, which do not express any of the RyR isoforms and lack E-C coupling (Buck et al., 1997; Moore et al., 1998; Fessenden et al., 2000; Kiselyov et al., 2000; Protasi et al., 2000; Ward et al., 2000) to C2C12 cells, which have wild type calcium signals (Estrada et al., 2001). Our data show that in the absence of RyR expression, cultured dyspedic skeletal myotubes retain the slow delayed intracellular calcium transient that is seen as a second phase of release after K+ depolarization in normal myotubes expressing RyR. This slow delayed release appears to require IP3 receptors that are expressed in both cell types. Our experimental evidence to support this hypothesis is summarized as follows: First, fast and slow calcium signals are detected in primary culture myotubes, as well as in a mouse muscle cell line, like C2C12, following depolarization induced by high potassium. Second, 1B5 "dyspedic" mice muscle cells, which do not express any of the ryanodine receptor isoforms (confirmed by [3H]-ryanodine binding and immunocytochemistry), show particularly notable nuclear calcium increases in response to K+ depolarization. The kinetics of this transient is comparable to those of the slow signal observed in rat and mouse primary cultures (Jaimovich and Rojas 1994; Estrada et al., 2000; Jaimovich et al., 2000) or C2C12 cells. Both the fast calcium transient, responsible for E-C coupling, and the fast-slow wave, associated with signal propagation, are absent in 1B5 myotubes. The fast calcium signal is restored in these cells upon re-expression of RyR1, but not RyR3 (Moore et al., 1998; Fessenden et al., 2000; Protasi et al., 2000, Galaz et al., 2001). Third, [3H]-IP3 binding and western blot analysis show the presence of IP3Rs in both 1B5 and C2C12 muscle cells. The presence of IP3R isoforms was confirmed by immunocytochemistry. Type 1 IP3Rs were localized preferentially to the nuclear envelope and both type 1 and type 3 IP3R immunoreactivity was higher in 1B5 cells compared to C2C12. Finally, in both 1B5 and C2C12 cells, K+ depolarization resulted in an increase in IP3 mass (Estrada et al., 2001). The kinetics of the IP3 mass transient is compatible with IP3 release preceding the calcium transient (see Figure 1).

Fig. 1: The scheme represents our present knowledge of the pathways involved either as causes or consequences of slow calcium waves induced by membrane depolarization in skeletal muscle cells. DHPR appears as the voltage sensor in the T-tubule membrane, communicating a signal (via a G-protein?) to phospholipase C (PLC). IP3 is liberated and diffuses to receptors located both in the SR region and in the nuclear envelope. Subsequent calcium increase will affect intracellular pathways, such as ERK 1/2 phosphorylation, CREB phosphorylation and regulation of early gene expression.

Calcium regulation of signal transduction and transcription in skeletal muscle

Calcium involvement in signaling pathways that lead to changes in gene expression is a well-established phenomenon. We have reported that depolarization of myotubes induces calcium signals both in cytosol and nucleus via IP3, as well as phosphorylation of extracellular signal-regulated kinases (ERK) 1/2 and the cAMP-response element-binding protein (CREB) (Powell et al., 2001). We have also shown (Carrasco et al., manuscript in preparation) that K+-induced depolarization of rat myotubes elicits a transient increase in mRNA levels of the early genes c-fos, c-jun and egr-1. Both CREB phosphorylation and activation of early genes were inhibited by blocking ERK phosphorylation. All three events (CREB phosphorylation, early gene expression and ERK phosphorylation) were maintained in the absence of extracellular calcium, while caffeine induced an increase in intracellular calcium that mimicked the depolarization stimulus. Depolarization either in the presence of 2APB (inhibitor of IP3 induced calcium release) or of cells loaded with BAPTA-AM, in which slow calcium signals were abolished, resulted in decreased activation of the three early genes mentioned above. The intracellular pathways implicated so far from our studies are summarized in figure 1.

In neurons, a number of calcium-dependent effects on transcription factors, such as CREB, and on early genes, such as c-fos, have been described. Depolarization induces ERK activation (see Rosen et al., 1994; Robertson et al., 1999; Vanhoutte et al., 1999), CREB phosphorylation and c-fos activation (reviewed in Ghosh and Greenberg, 1995; Bito et al., 1997; Hardingham and Bading, 1999). The c-fos gene has two major calcium-responsive regulatory elements in its promoter region, the CRE (calcium/cAMP responsive element) and the SRE (serum response element). In neurons, Ca2+ influx, as result of membrane depolarization (or NMDA receptor activation), stimulates CREB phosphorylation, a response necessary for CRE-mediated transcription. The role of Ca2+is to enhance the activity of Ca2+-dependent kinases that phosphorylate CREB, as has been demonstrated in several neuronal and non-neuronal models (Hardingham and Bading, 1999; Shaywitz and Greenberg, 1999). Phosphorylated CREB recruits CBP (CREB binding protein), a transcriptional co-activator, and studies concerning the calcium requirement for both CREB phosphorylation and CBP activity have yielded very interesting insights to the mechanism of transcriptional regulation by calcium (Bading, 2000). Briefly, CREB phosphorylation was found to be necessary but not sufficient for transcription to occur (Chawla et al., 1998) and changes in nuclear rather than cytoplasmic Ca2+ were able to induce CBP activation, presumably by phosphorylation (Chawla et al., 1998; Hu et al., 1999). Serine 301 has been recently identified as the relevant CBP phosphorylation site (Impey et al., 2002). Since CBP interacts with many transcription factors in addition to CREB, CBP activation provides a mechanism by which nuclear Ca2+ stimulates a large number of transcription factors, including c-jun, and the expression of many genes (reviewed in Bading, 2000). SRE, the other calcium-responsive element in the c-fos promoter, contains two binding sites, one for the serum response factor (SRF) and another for ternary complex factors (TCF) of the Elk-1 family of ETS domain transcription factors. In this manner, SRE functions as an integrator of two calcium signaling pathways. Interestingly, SRE responds in neurons to cytoplasmic calcium , as opposed to CRE-mediated transcription which requires nuclear calcium (Hardingham and Bading, 1999).

In skeletal muscle cells, two major stimuli have been identified for growth and gene expression: electrical muscle activity (involving membrane depolarization) and growth factors. Muscle activity has long been known to stimulate (Brevet et al., 1976) or inhibit (Cohen and Fischbach, 1973) the production of extrajunctional muscle specific proteins, yet the series of molecular events linking muscle activity to cellular expression and accumulation of contractile proteins has not been defined. Activation of the ERK isoforms 1 and 2, as a consequence of muscle stimulation, has been widely reported (see for instance Goodyear et al., 1996; Sherwood et al., 1999; Ryder et al., 2000). However, a specific role for these MAP kinases in skeletal muscle gene expression was only recently demonstrated (Murgia et al., 2000). In regenerating muscle, transfection of constitutively active Ras and a Ras mutant that selectively activates ERKs, could mimic the effects of slow motor neuron activity on myosin gene expression. Several reports have shown that exercise or electrical activity increase early gene mRNA levels (Abu-Shakra et al., 1994; Michel et al., 1994: Osbaldeston et al., 1995; Aronson et al., 1997; Punschart et al., 1998). Since most immediate early gene products are transcription factors that bind to specific promoter sequences and regulate expression of downstream genes, they are likely to be involved in adaptative responses induced by neural activity and contractile work in skeletal muscle.

Intracellular calcium response in skeletal muscle cell cultures can be mediated by hormones and neurotransmitters

We have identified (Reyes and Jaimovich, 1996) the presence of functional muscarinic receptors in cultured muscle cells. Either muscarine or carbachol induced IP3 increases that were associated with calcium transients in these cells, suggesting the presence of a metabotropic, G-protein mediated pathway.

Fast, non-genomic steroid actions in several cell types seem to be mediated by second messengers such as intracellular Ca2+ and IP3. We have studied the effect of steroids on intracellular calcium by monitoring Fluo 3-AM loaded myotubes using either confocal or fluorescence microscopy. We observed (Estrada et al., 2000) intracellular calcium changes after either aldosterone (10-100 nM) or testosterone (10 nM) addition. A relatively fast (less than 2 min) calcium transient, frequently accompanied by oscillations, was observed with both hormones. A slow rise in intracellular Ca2+ that reached its maximum after 30 min was seen upon exposure to aldosterone. Calcium responses appear to be fairly specific for aldosterone and testosterone, as several other steroid hormones do not induce detectable changes in fluorescence even at 100-fold higher concentrations. The mass of IP3 increased transiently to values 2-3 fold higher than the basal levels, 45 seconds after addition of either aldosterone or testosterone. The IP3 transient was more rapid than the hormone induced fast calcium signal. Spironolactone, an inhibitor of the intracellular aldosterone receptor or cyproterone, an inhibitor of the testosterone receptor neither affected the fast Ca2+ signal, nor the increase in IP3 mass (Estrada et. al., 2000, Estrada and Jaimovich, 2001). Taken together, these results indicate that distinct non-genomic signaling pathways exist for the action of these two steroids in skeletal muscle cells.


This work was supported by FONDECYT No. 8980010 and FONDAP 15010006.


ABU-SHAKRA S, COLE AJ, DRACHMAN DB (1994) Cholinergic stimulation of skeletal muscle cells induces rapid immediate early gene expression: role of intracellular calcium. Brain Res Mol Brain Res 26: 55-60

ARONSON D, DUFRESNE SD, GOODYEAR LJ (1997) Contractile activity stimulates the c-jun NH2-terminal kinase pathway in rat skeletal muscle. J Biol Chem 272: 25636-25640

BADING H (2000) Transcription-dependent neuronal plasticity. The nuclear calcium hypothesis. Eur.J. Biochem 267: 5280-5283

BERRIDGE MJ (1993) Inositol trisphosphate and calcium signaling. Nature 361: 315-325

BERRIDGE MJ, LIPP P, BOOTMAN MD (2000) The versatility and universality of calcium signaling. Nature Reviews in Molecular Cell Biology 1: 11-21

BITO H, DEISSEROTH K, TSIEN RW (1997) Ca2+-dependent regulation in neuronal gene expression. Current Op Neurobiol 7: 419-429

BREVET A, PINTO E, PEACOCK J, STOCKDALE FE (1976) Myosin synthesis increased by electrical stimulation of skeletal muscle cell cultures. Science 193: 1152-1154

BUCK ED, NGUYEN H, PESSAH IN, ALLEN PD (1997) Dyspedic mouse skeletal muscle expresses major elements of the triadic junction but lacks detectable ryanodine receptor protein and function. J Biol Chem 272: 7360-7367

CARRASCO MA, FIGUEROA S (1995) Inositol 1,4,5-trisphosphate 3-kinase activity in frog skeletal muscle. Comp Biochem Physiol B Biochem Mol Biol 110: 747-753

CARRASCO MA, MAGENDZO K, JAIMOVICH E, HIDALGO C (1988) Calcium modulation of phosphoinositide kinases in transverse tubule vesicles from frog skeletal muscle. Arch Biochem Biophys 262: 360-366

CARRASCO MA, SIERRALTA J, DE MAZANCOURT P (1994) Characterization and subcellular distribution of G-proteins in highly purified skeletal muscle fractions from rabbit and frog. Arch Biochem Biophys 310: 76-81

CARRASCO MA, SIERRALTA J, HIDALGO C (1993) Phospholipase C activity in membranes and a soluble fraction isolated from frog skeletal muscle. Biochim Biophys Acta 1152: 44-48

CHAWLA S, HARDINGHAM GE, QUINN DR, BADING H (1998) CBP: a signal-regulated transcriptional coactivator controlled by nuclear calcium and CaM kinase IV. Science 281: 1505-1509

COHEN SA, FISCHBACH GD (1973) Regulation of muscle acetylcholine sensitivity by muscle activity in cell culture. Science 181: 76-78

DE SMEDT H, MISSIAEN L, PARYS JB, HENNING RH, SIENAERT I, VANLINGEN S, GIJSENS A, HIMPENS B, CASTEELS R (1997) Isoform diversity of the inositol trisphosphate receptor in cell types of mouse origin. Biochem J 322: 575-583

ESTRADA M, LIBERONA J L, MIRANDA M, JAIMOVICH E (2000) Aldosterone- and testosterone-mediated intracellular calcium response in skeletal muscle cell cultures. Am J Physiol Endocrinol Metab 279: E132-139

ESTRADA M, JAIMOVICH E (2001) Testosterone induces both intracellular calcium increases and ERK phosphorylation independent of androgen receptor in muscle cells. Biol Res 34: R-141

ESTRADA M, CARDENAS C, LIBERONA JL, CARRASCO MA, MIGNERY GA, ALLEN PD, JAIMOVICH E (2001) Calcium transients in 1B5 myotubes lacking ryanodine receptors are related to inositol trisphosphate receptors. J Biol Chem 276: 22868-22874

FESSENDEN JD, WANG Y, MOORE RA, CHEN SR, ALLEN PD, PESSAH IN (2000) Divergent functional properties of ryanodine receptor types 1 and 3 expressed in a myogenic cell line. Biophys J 79: 2509-25

FLUCHER BE, ANDREWS SB (1993) Characterization of spontaneous and action potential-induced calcium transients in developing myotubes in vitro. Cell Motil Cytoskeleton 25: 143-157

GALAZ J, ESPINOSA A, ESTRADA M, CARRASCO MA, ALLEN P, JAIMOVICH E (2001) Functional restoration of ryanodine receptor in 1B5 muscle cells. Biol Res 34: R-141

GHOSH A, GREENBERG ME (1995) Calcium signaling in neurons: molecular mechanisms and cellular consequences. Science 268: 239-247

GOODYEAR LJ, CHANG PY, SHERWOOD DJ, DUFRESNE SD, MOLLER DE (1996) Effects of exercise and insulin on mitogen-activated protein kinase signaling pathways in rat skeletal muscle. Am J Physiol 271: E403-408

GUIHARD G, PROTEAU S, ROUSSEAU E (1997) Does the nuclear envelope contain two types of ligand-gated Ca2+ release channels? FEBS Lett 414: 89-94

HARDINGHAM GE, BADING H (1999) Calcium as a versatile second messenger in the control of gene expression. Microsc Res Tech 46: 348-355

HIDALGO C, CARRASCO MA, MAGENDZO C, JAIMOVICH E (1986) Phosphorylation of phosphatidylinositol by transverse tubule vesicles and its possible role in excitation - contraction coupling. FEBS Lett 202: 69-73

HIDALGO C, ARACENA P, SANCHEZ G, DONOSO P (2002) Redox regulation of calcium release in skeletal and cardiac muscle. Biol Res 35: 183-193

HU SC, CHRIVIA J, GHOSH A (1999) Regulation of CBP-mediated transcription by neuronal calcium signaling. Neuron 22: 799-808

HUMBERT JP, MATTER N, ARTAULT JC, KOPPLER P, MALVIYA AN (1996) Inositol 1,4,5-trisphosphate receptor is located to the inner nuclear membrane vindicating regulation of nuclear calcium signaling by inositol 1,4,5-trisphosphate. J Biol Chem 271: 478-485

IMPEY S, FONG AL, WANG Y, CARDINAUX J-R, FASS DM, OBRIETAN K, WAYMAN GA, STORM DR, SODERLIGING TR, GOODMAN RH (2002) Phosphorylation of CBP mediates transcriptional activation by neural activity and CaM kinase IV. Neuron 34: 235-244

JAIMOVICH E (1991) Chemical transmission at the triad: InsP3? J Musc Res Cell Motil 12: 316-320

JAIMOVICH E, ROJAS E (1994) Intracellular Ca2+ transients induced by high external K+ and tetracaine in cultured rat myotubes. Cell Calcium 15: 356-368

JAIMOVICH E, REYES R, LIBERONA J, POWELL JA (2000) IP3receptors, IP(3) transients, and nucleus-associated Ca2+ signals in cultured skeletal muscle. Am J Physiol Cell Physiol 278: C998-C1010

KISELYOV KI, SHIN DM, WANG Y, PESSAH IN, ALLEN PD, MUALLEM S (2000) Gating of store-operated channels by conformational coupling to ryanodine receptors. Mol Cell 6: 421-431

LIBERONA JL, POWELL JA, SHENOI S, PETHERBRIDGE L, CAVIEDES R, JAIMOVICH E (1998) Differences in both inositol 1,4,5-trisphosphate mass and inositol 1,4,5-trisphosphate receptors between normal and dystrophic skeletal muscle cell lines. Muscle and Nerve 21: 902-909

MICHEL JB, ORDWAY GA, RICHARDSON JA, WILLIAMS RS (1994) Biphasic induction of immediate early gene expression accompanies activity-dependent angiogenesis and myofiber remodeling of rabbit skeletal muscle. J Clin Invest 94: 277-285

MOORE RA, NGUYEN H, GALCERAN J, PESSAH IN, ALLEN PD (1998) A transgenic myogenic cell line lacking ryanodine receptor protein for homologous expression studies: reconstitution of Ry1R protein and function. J Cell Biol 140: 843-51

MURGIA M, SERRANO AL, CALABRIA E, PALLAFACCHINA G, LOMO T, SCHIAFFINO S (2000). Ras is involved in nerve-activity-dependent regulation of muscle genes. Nat Cell Biol 2: 142-147

NEWTON CL, MIGNERY GA, SUDHOF TC (1994) Co-expression in vertebrate tissues and cell lines of multiple inositol 1,4,5-trisphosphate (InsP3) receptors with distinct affinities for InsP3. J Biol Chem 269: 28613-28619

OSBALDESTON NJ, LEE DM, COX VM, HESKETH JE, MORRISON JFJ, BLAIR GE, GOLDSPINK DF (1995) The temporal and cellular expression of c-fos and c-jun in mechanically stimulated rabbit latissimus dorsi muscle. Biochem J 308: 465-471

PETERSEN OH (2002) Calcium signal compartmentalization. Biol Res 35: 177-182

PETERSEN OH, GERASIMENKO OV, GERASIMENKO JV, MOGAMI H, TEPIKIN A V (1998) The calcium store in the nuclear envelope. Cell Calcium 23: 87-90

POWELL JA, PETHERBRIDGE L, FLUCHER BE (1996) Formation of triads without the dihydropyridine receptor alpha subunits in cell lines from dysgenic skeletal muscle. J Cell Biol 134: 375-387

POWELL J, CARRASCO MA, ADAMS DS, DROUET B, RIOS J, MULLER M, ESTRADA M, JAIMOVICH E (2001a) IP3 receptor function and localization in myotubes: an unexplored Ca2+ signaling pathway in skeletal muscle. J Cell Sci 114: 3673-3683

POWELL JA, ADAMS DS, MOLGO J, COLASSANTE C, WILLIAMS A, BOHLEN MK, JAIMOVICH E (2001b) IP3 receptor function and localization in skeletal muscle in vitro and in vivo: A new calcium signaling pathway in muscle. Biol Res 34: R-9

PROTASI F, TAKEKURA H, WANG Y, CHEN SR, MEISSNER G, ALLEN PD, FRANZINI-ARMSTRONG C (2000) RYR1 and RYR3 have different roles in the assembly of calcium release units of skeletal muscle. Biophys J .79: 2494-508

PUNTSCHART A, WEY E, JOSTARDNDT K, VOGT M, WITTWER M, WIDMER HR, HOPPELER H, BILLETER R (1998) Expression of fos and jun genes in human skeletal muscle after exercise. Am J Physiol 274: C129-137

REYES R, JAIMOVICH E (1996) Functional muscarinic receptors in cultured skeletal muscle. Arch Biochem Biophys 331: 41-47

ROBERTSON ED, ENGLISH JD, ADAMS JP, SELCHER JC, KONDRATICK C, SWEATT JD (1999) The mitogen-activated protein kinase cascade couples PKA and PKC to cAMP response element binding protein phosphorylation in area CA1 of hippocampus. J Neurosci 19: 4337-4348

ROJAS C, JAIMOVICH E (1990) Calcium release modulated by inositol trisphosphate in ruptured fibers from frog skeletal muscle. Pflügers Arch (Eur J Physiol): 416: 296-304

ROSEN LB, GINTY DD, WEBER MJ, GREENBERG ME (1994) Membrane depolarization and calcium influx stimulate MEK and MAP kinase via activation of Ras. Neuron 12: 1207-1221

RYDER JW, FAHLMAN R, WALLBERG-HENRIKSSON H, ALESSI DR, KROOK A, ZIERATH JR (2000) Effect of contraction on mitogen-activated protein kinase signal transduction in skeletal muscle of the mitogen- and stress- activated protein kinase 1. J Biol Chem 275: 1457-1462

SANCHEZ X, CARRASCO MA, VERGARA J, HIDALGO C (1991) Inositol 1,4,5-triphosphate phosphatase activity in membranes isolated from amphibian skeletal muscle [corrected] [published erratum appears in FEBS Lett (1991) 284:142]. FEBS Lett 279: 58-60

SCHERER NM, TORO MJ, ENTMAN ML, BIRNBAUMER L (1987) G-protein distribution in canine cardiac sarcoplasmic reticulum and sarcolemma: comparison to rabbit skeletal muscle membranes and to brain and erythrocyte G-proteins. Arch Biochem Biophys 259: 431-440

SHAYWITZ AJ, GREENBERG ME (1999) CREB: a stimulus-induced transcription factor activated by a diverse array of extracellular signals. Annu Rev Biochem 68: 821-861

SHERWOOD DJ, DUFRESNE SD, MARKUNS JF, CHEATHAM B, MOLLER DE, ARONSON D, GOODYEAR LJ (1999) Differential regulation of MAP kinase, p70(S6K), and Akt by contraction and insulin in rat skeletal muscle. Am J Physiol 276: E870-878

SUAREZ-ISLA BA, IRRIBARRA V, OBERHAUSER A, LARRALDE L, BULL R, HIDALGO C, JAIMOVICH E (1988) Inositol (1,4,5)-trisphosphate activates a calcium channel in isolated sarcoplasmic reticulum membranes. Biophys J 54: 737-741

VANHOUTTE P, BARNIER JV, GUIBERT B, PAGES C, BESSON MJ, HIPSKIND RA, CABOCHE J (1999) Glutamate induces phosphorylation of Elk-1 and CREB along with c-fos activation, via an extracellular signal-regulated kinase-dependent pathway in brain slices. Mol Cell Biol 19: 136-146

VOLPE P, DI VIRGILIO F, POZZAN T, SALVIATI G (1986) Role of inositol 1,4,5-trisphosphate in excitation-contraction coupling in skeletal muscle. FEBS Lett 197: 1-4

WARD CW, SCHNEIDER MF, CASTILLO D, PROTASI F, WANG Y, CHEN SRW, ALLEN PD (2000) Expression of ryanodine receptor RyR3 produces Ca2+ sparks in dyspedic myotubes. J Physiol 525 Pt 1:91-103

WOJCIKIEWICZ J (1995) Type I, II, and III inositol 1,4,5-trisphosphate receptors are unequally susceptible to down-regulation and are expressed in markedly different proportions in different cell types. J Biol Chem 270: 11678-11683

Corresponding author: E. Jaimovich, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile Casilla 70005, Santiago 6530499, Chile. Phone: (56-2) 678-6311; FAX: (56-2) 777-6916; e-mail:

Received: June 05, 2002. In revised form: July 03, 2002. Accepted: July 14, 2002

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