Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Calponins”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5Linked to original sources
PubMed2006

Change in the shape and density of dendritic spines caused by overexpression of acidic calponin in cultured hippocampal neurons.

Dendritic spines are morphing structures believed to provide a cellular substrate for synaptic plasticity. It has been suggested that the actin cytoskeleton is the target of molecular mechanisms regulating spine morphology. Here we hypothesized that acidic calponin, an actin-binding protein, is one of the key regulators of actin filaments during spine plasticity. Our data showed that the overexpression of acidic calponin-GFP (green fluorescent protein) in primary cultures of rat hippocampal neurons causes an elongation of spines and an increase of their density as compared with those of GFP-expressing neurons. These effects required the actin-binding domains of acidic calponin. The close apposition of the presynatic marker synaptophysin to these long spines and the presence of specific postsynaptic markers actin, PSD-95, NR1, and GluR1 suggested the existence of functional excitatory synaptic contacts. Indeed, electrophysiological data showed that the postsynaptic overexpression of acidic calponin enhanced the frequency of miniature excitatory postsynaptic currents as compared with that of GFP-expressing neurons, but did not affect their properties such as amplitude, rise time, and half width. Studies in heterologous cells revealed that acidic calponin reorganized the actin filaments and stabilized them. Taken together, these findings show that acidic calponin regulates dendritic spine morphology and density, likely via regulation of the actin cytoskeleton reorganization and dynamic. Furthermore, the acidic calponin-induced spines are able to establish functional glutamatergic synapses. Such data suggest that acidic calponin is a key factor in the regulation of spine plasticity and synaptic activity.

Actins↗
PubMed1994

Effects of exogenously applied calponin on Ca(2+)-regulated force in skinned smooth muscle of the rabbit mesenteric artery.

To help elucidate the physiological role of calponin (a thin-filament-linked regulatory protein) in smooth muscle contraction, the effects of its exogenous application were investigated on actin-activated MgAT-Pase activity in crude actomyosin from chicken gizzard, and on contraction induced by Ca(2+)-dependent and -independent means in arterial smooth muscle strips skinned by saponin or beta-escin. Calponin concentration dependently inhibited actin-activated MgATPase activity with a proportional increase in its binding to actomyosin and also attenuated Ca(2+)-induced contractions, in the presence or absence of calmodulin, in skinned arterial strips. Calponin, when phosphorylated by protein kinase C, reduced both its ability to bind to actomyosin and its inhibitory action on actomyosin MgATPase. The phosphorylated calponin also had no effect on the maximum Ca(2+)-induced contraction in skinned smooth muscle, suggesting that these actions of calponin are not nonspecific. Calponin attenuated the Ca(2+)-independent contraction observed in myosin light chain thio-phosphorylated strips, or on application of trypsin-treated myosin light chain kinase. However, calponin had no effect on maintained rigor contraction. These results suggest that in vascular smooth muscle, calponin may play a physiological role in the inhibition of Ca(2+)-regulated force, possibly through a direct action on active actin-myosin interactions.

Adenosine Triphosphate↗
PubMed2001

Immunolocalization of the 38.3 kDa calponin-like protein in stratified muscles of the tail of Schistosoma japonicum cercariae.

Calponins are proteins present in vertebrate smooth musculature where they occur in association with thin myofilaments. Calponins are not present in vertebrate or invertebrate striated muscles. The blood fluke Schistosoma japonicum expresses a 38.3-kDa protein that bears substantial homology with vertebrate calponin and occurs entirely within smooth musculature of adults. Calponin-like immunoreactivity has been demonstrated in smooth muscles of many invertebrate phyla. The Schistosoma japonicum calponin has been localised in smooth myofibrils of adults where it is associated with myofilaments and sarcoplasmic reticulum. In this study, the ultrastructural localisation of the protein in muscles of S. japonicum cercariae is described. The protein is present in smooth muscles of the forebody and the stratified muscle of the tail. Within the stratified layer, the protein occurs predominantly in transverse arrays of sarcoplasmic reticulum. The localisation data suggest that the calponin-like protein of S. japonicum is involved in contraction of the stratified tail muscle. Furthermore, the presence of a calponin system in the stratified muscle suggests that this muscle is simply a superior form of muscle, closely related to smooth muscles that use a caldesmin-calponin system in contraction.

Actin Cytoskeleton↗
PubMed1995

Characterization of calponin binding to actin.

Calponin, a protein isolated from smooth muscle and nonmuscle cells, has previously been shown to inhibit the actin-activated ATPase activity of myosin. Reports of the stoichiometry of binding range from 1 calponin per actin to 1 calponin per 3 actin monomers. We now report a detailed study of the binding of [14C]iodoacetamide-labeled calponin to actin. The labeling procedure did not significantly alter the binding constant of calponin to actin. The stoichiometry of binding was variable and dependent on ionic strength. Below 110 mM ionic strength, the stoichiometry of binding was 1:1. As the ionic strength was increased above 110 mM ionic strength, the stoichiometry shifted from 1:1 to 1 calponin per 2 actin monomers. At physiological ionic strength, the binding exhibited a small degree of positive cooperativity and was adequately described by a single class of binding sites with an association constant of 6 x 10(6) M-1. The affinity decreased to 20% of this value in the presence of ATP. Irrespective of the ionic strength, actin formed bundles when saturation with calponin exceeded about 30%. Measurements of the rate of association were complicated by this bundling, but the upper limit for this reaction was placed at 10(6) M-1 s-1. The addition of calponin to actin-caldesmon complexes caused displacement of the caldesmon.

Actins↗
PubMed1996

Modulation of actin conformation and inhibition of actin filament velocity by calponin.

Calponin, an actin/calmodulin-binding protein present in smooth muscle thin filaments, modulates the actin-myosin interaction and actomyosin ATPase activity of smooth muscle myosin II. Binding of myosin heads to actin under conditions that produce weak or strong binding induces conformational changes in actin. Polarized fluorimetric measurements of rhodamine-phalloidin complex and 1,5-IAEDANS specifically linked to actin in myosin-free muscle fibers (ghost fibers) and to Cys-707 in myosin head, respectively, revealed conformational changes, as determined from the changes in orientation and mobility of fluorescent probes, upon addition of calponin to ghost fibers. The effect of calponin on conformational changes produced upon binding of phosphorylated or dephosphorylated heavy meromyosin (HMM) was also determined. Subfragment-1 preparation modified with NEM (NEM-S1) or pPDM (pPDM-S1) were used as models of strong and weak binding, respectively. Calponin changed both the orientation of fluorophores on the actin and the flexibility of the actin filaments, as determined from the angle between an actin filament and the fiber axis. Changes in the flexibility of actin filaments and the orientation of fluorophores produced by phosphorylated smooth muscle HMM were similar to those seen with NEM-S1, which formed a strong-binding association with actin and caused the transition of actin monomers to the "on" state; calponin markedly inhibited this effect. In contrast, pPDM-S1 and dephosphorylated HMM induced weak binding and the transition of actin monomers to the "of" state, and these effects were enhanced by calponin. Furthermore, calponin decreased the velocity of actin filament movement over skeletal muscle myosin O gamma phosphorylated smooth muscle myosin heads in an in vitro motility assay. These results suggest that calponin induces modulation of smooth muscle contraction by inhibiting the force-producing (strong-binding) state of cross-bridges and involves changes in actin conformation.

Actins↗
PubMed1993

Calponin phosphorylation in vitro and in intact muscle.

Calponin, a thin-filament-associated protein implicated in the regulation of smooth-muscle contraction, is phosphorylated in vitro by protein kinase C and Ca2+/calmodulin-dependent protein kinase II [Winder and Walsh (1990) J. Biol. Chem. 265, 10148-10155] and dephosphorylated by a type 2A protein phosphatase [Winder, Pato and Walsh (1992) Biochem. J. 286, 197-203]. Unphosphorylated calponin binds to actin and inhibits the actin-activated myosin MgATPase; these properties are lost on phosphorylation. Although both serine and threonine residues in calponin are phosphorylated, the major site of phosphorylation by either kinase is Ser-175. Calponin also undergoes phosphorylation when bound to actin in synthetic thin filaments, in a reconstituted actomyosin system, in washed myofibrils and in tissue extracts; this results in dissociation of calponin from actin. Tryptic phosphopeptide mapping indicates that the same sites are phosphorylated in the bound as in the isolated protein. Toad stomach calponin exists in at least three isoforms which differ in charge but exhibit the same molecular mass on SDS/PAGE. In a toad stomach extract, all three isoforms are phosphorylated by protein kinase C or Ca2+/calmodulin-dependent protein kinase II as shown by two-dimensional gel electrophoresis (non-equilibrium pH-gradient gel electrophoresis and SDS/PAGE). Calponin phosphorylation also occurs in intact toad stomach smooth-muscle strips metabolically labelled with 32Pi and stimulated to contract with carbachol. These results support the hypothesis that calponin may be regulated in vivo by phosphorylation-dephosphorylation.

Amino Acid Sequence↗
PubMed1995

Physical characterization of calponin. A circular dichroism, analytical ultracentrifuge, and electron microscopy study.

Calponin is a thin filament-associated smooth muscle protein that has been suggested to play a role in the regulation of smooth muscle contraction. We have used circular dichroism spectroscopy, electron microscopy, and analytical ultracentrifugation to study the physical properties of recombinant chicken gizzard alpha-calponin. The alpha-helix content of alpha-calponin was estimated from its circular dichroism spectrum to be approximately 13%, alpha-Calponin melts with a single sharp transition at approximately 57 degrees C. Rotary shadowing electron micrographs of alpha-calponin reveal diverse shapes ranging from elongated rods to collapsed coils. The lengths of the rod-shaped structures are approximately 18 nm. Analytical ultracentrifugation studies found alpha-calponin to be homogeneous with a monomer molecular mass of 31.4 kDa, and a s20,w value of 2.34 S. These data could be used to model alpha-calponin as a prolate ellipsoid of revolution with an axial ratio of 6.16, a length of 16.2 nm, and a diameter of 2.6 nm. Taken together, our results indicate that calponin is a flexible, elongated molecule whose contour length is sufficient to span three actin subunits along the long pitch helix of an F-actin filament.

Animals↗
PubMed1996

Developmental pattern of expression and genomic organization of the calponin-h1 gene. A contractile smooth muscle cell marker.

Calponin-h1 is a 34-kDa myofibrillar thin filament, actin-binding protein that is expressed exclusively in smooth muscle cells (SMCs) in adult animals. To examine the molecular mechanisms that regulate SMC-specific gene expression, we have examined the temporal, spatial, and cell cycle-regulated patterns of expression of calponin-h1 gene expression and isolated and structurally characterized the murine calponin-h1 gene. Calponin-h1 mRNA is expressed exclusively in SMC-containing tissues in adult animals. During murine embryonic development, calponin-h1 gene expression is (i) detectable in E9.5 embryos in the dorsal aorta, cardiac outflow tract, and tubular heart, (ii) sequentially up-regulated in SMC-containing tissues, and (iii) down-regulated to non-detectable levels in the heart during late fetal development. In addition, the gene is expressed in resting rat aortic SMCs, but its expression is rapidly down-regulated when growth-arrested cells reenter phase G1 of the cell cycle and proliferate. Calponin-h1 is encoded by a 10.7-kilobase single copy gene composed of seven exons, which is part of a multigene family. Transient transfection analyses demonstrated that 1.5 kilobases of calponin-h1 5'-flanking sequence is sufficient to program high level transcription of a luciferase reporter gene in cultured primary rat aortic SMCs and the smooth muscle cell line, A7r5. Taken together, these data suggest that the calponin-h1 gene will serve as an excellent model system with which to examine the molecular mechanisms that regulate SMC lineage specification, differentiation, and phenotypic modulation.

Amino Acid Sequence↗
PubMed1996

The effects of smooth muscle calponin on the strong and weak myosin binding sites of F-actin.

We have investigated the mechanism of inhibition of the actomyosin MgATPase by the smooth muscle protein calponin. We have shown previously the specific interaction of calponin with Glu334 of actin (EL-Mezgueldi, M., Fattoum, A., Derancourt, J., and Kassab, R. (1992) J. Biol. Chem. 267, 15943-15951). This residue is within the sequence 332-334, which has been proposed to be an important part of the strong myosin binding site (Rayment, I., Holden, H. M., Whittaker, M., Yohn, C. B., Lorenz, M., Holmes, K. C., and Milligan, R. A. (1993) Science 261, 58-65). Therefore, we suggested that calponin will affect the strong binding actin-myosin interaction. To test this hypothesis we have investigated the effect of calponin on the strong binding of S-1.MgAMP-PNP (5'-adenylyl imidodiphosphate) and on the weak binding of S-1.MgADP.Pi to actin. We found that an inhibitory concentration of calponin decreased the binding of S-1. MgAMP-PNP to actin but had no effect on the binding of S-1.MgADP.Pi. Similar results were obtained with skeletal muscle and smooth muscle S-1. In competition experiments calponin was found to displace S-1. MgAMP-PNP and S-1.MgADP but not S-1.MgADP.Pi from the actin filament. S-1 displaced calponin from actin in the rigor state, in the presence of MgADP, and in the presence of MgAMP-PNP. We conclude that calponin inhibits the actin activated S-1 ATPase by blocking a strong S-1 binding site on actin and does not block the weak binding site.

Actins↗
PubMed1996

Strong interaction between caldesmon and calponin.

Caldesmon was labeled at either Cys-153 in the NH2-terminal domain or Cys-580 in the COOH-terminal domain with a 6-acryloyl-2-dimethylaminonaphthalene (acrylodan) fluorescence probe. The addition of smooth muscle calponin to Cys-580-labeled caldesmon resulted in an 18% drop in fluorescence intensity, which titrated with a stoichiometry of 0.9 and a binding constant of 9.5 x 10(7) M-1. For Cys-153-labeled caldesmon, there was no change in fluorescence upon adding calponin. These findings indicate strong binding between calponin and the COOH-domain of caldesmon. The association was sensitive to ionic strength, suggesting that ionic interactions between calponin, a basic protein, and caldesmon, an acidic protein, contribute to the stabilization of the protein complex. That non-muscle acidic calponin interacts with caldesmon with a much reduced association constant of 3.5 x 10(6) M-1 supports such a model. The binding between acidic calponin and caldesmon is strengthened to 1.8 x 10(7) M-1 in the presence of Ca2+, which might bind to acidic residues of the calponin and partially neutralize its negative charge. The strong, specific binding between calponin and caldesmon suggests that this interaction occurs within smooth muscle cells and possibly plays a role in the regulation of contraction.

Animals↗
PubMed1997

Localization of protein regions involved in the interaction between calponin and myosin.

Calponin is a 33-kDa smooth muscle-specific protein that has been suggested to play a role in muscle contractility. It has previously been shown to interact with actin, tropomyosin, and calmodulin. More recently we showed that calponin also interacts with myosin (Szymanski, P. T., and Tao, T. (1993) FEBS Lett. 331, 256-259). In the present study we used a combination of co-sedimentation and fluorescence assays to localize the regions in myosin and calponin that are involved in the interaction between these two proteins. We found that recombinant chicken gizzard alpha-calponin co-sediments with myosin rod and, to a lesser extent, with light meromyosin. Fluorescently labeled recombinant calponin shows interaction with heavy meromyosin and myosin subfragment 2 but not subfragment 1. A fragment comprising residues 7-182 and a synthetic peptide spanning residues 146-176 of calponin co-sediment with myosin, but fragments comprising residues 7-144 and 183-292 do not. Our results indicate that there are calponin binding sites in the subfragment 2 and light meromyosin regions of myosin, and that the region comprising residues 145-182 of calponin mediates its interaction with myosin.

Amino Acid Sequence↗
PubMed1993

Characterization of wild type and mutant chicken gizzard alpha calponin expressed in E. coli.

Calponin is a thin filament-associated protein that is implicated in the regulation and maintenance of smooth muscle contraction. Molecular cloning of chicken gizzard calponin indicated the presence of two isoforms, alpha and beta, the expression of the alpha-isoform being uniformly more abundant in various smooth muscle tissues [Takahashi, K. & Nadal-Ginard, B. (1991) J. Biol. Chem. 266, 13284-13288]. For the long-range goal of understanding of the structure and function of calponin, we have started bacterial expression and site-directed mutagenesis of alpha calponin. The amino acid composition and N-terminal sequence of the recombinant alpha calponin were found to be identical to those deduced from its nucleotide sequence. Recombinant alpha calponin is capable of binding to calmodulin, troponin C, tropomyosin, and actin, and of inhibiting skeletal muscle acto-subfragment-1 ATPase activity. A mutant alpha calponin with a replacement in the putative inhibitory region (residues 146-171) has impaired ability to inhibit the acto-subfragment-1 ATPase activity, suggesting that this region of calponin may be involved in the modulation of the actin-myosin interactions.

Actins↗
PubMed1994

Calcium-dependent regulation of smooth muscle calponin by S100.

Calponin, a major calmodulin-, actin-, and tropomyosin-binding protein in smooth muscle, interacted with brain S100 and the properties of the interaction were investigated in detail. From fluorescence labeling and chemical cross-linking experiments, the apparent Kd value was calculated to be 7 x 10(7) M-1 in the presence of Ca2+ with 1 mol of S100 bound per mol of calponin. The addition of S100 to the mixture of calponin and F-actin caused the removal of calponin from actin filaments in the presence of Ca2+ but not in the presence of EGTA or Zn2+. Ca2+ and S100 could relieve calponin-induced actomyosin Mg(2+)-ATPase inhibition. Both the removal of calponin from F-actin and the restoration of ATPase inhibition by S100 were more effective than those by calmodulin. At low ionic strength, the binding was observed irrespective of Ca2+ concentration and it was greatly weakened with increasing salt concentration. The formation of the complex in the presence of Ca2+ was less sensitive, with only 45% inhibition at 100 mM NaCl, where the complex in the absence of Ca2+ had almost disappeared. This was confirmed by S-100 Sepharose 4B chromatography. Addition of Ca2+ and S100 also led to a decrease in the affinity of calponin for tropomyosin. Domain mapping with chymotryptic digestion revealed that the S100 binding site resided within the N-terminal 22 kDa fragment of calponin, where the bindings of calmodulin and actin also occur.

Actins↗
PubMed1997

Calponin inhibits actin-activated MgATPase of myosin subfragment 1 (S1) without displacing S1 from its binding site on actin.

Calponin is a smooth-muscle thin-filament protein implicated in the regulation of contraction. Its binding to actin is a prerequisite for inhibition of actin-activated myosin MgATPase. Investigating the molecular mechanism of this inhibition, it was found that titration of acto-myosin subfragment 1 with calponin in the presence of either ADP or ATP does not displace weakly or strongly bound myosin subfragment 1 (S1) from actin. S1.ADP, however, is able to release about two-thirds of the calponin from saturated (equimolar) complexes of actin-calponin. The remaining calponin is sufficient for almost full inhibition of acto-S1 MgATPase activity. Bunding of actin filaments by calponin takes place at a higher ratio calponin/actin (above 1:3) and, therefore, is not responsible for inhibition of the ATPase. Bundle formation is inhibited by S1.ADP. These results suggest the existence of two calponin-binding sites on actin; one, that is insensitive to S1, which is responsible for inhibition of the ATPase, the other, from which calponin is readily displaced by S1.

Actins↗
PubMed2000

Contractile properties and proteins of smooth muscles of a calponin knockout mouse.

The role of h1-calponin in regulating the contractile properties of smooth muscle was investigated in bladder and vas deferens of mice carrying a targeted mutation in both alleles designed to inactivate the basic calponin gene. These calponin knockout (KO) mice displayed no detectable h1-calponin in their smooth muscles. The amplitudes of Ca2+ sensitization, force and Ca2+ sensitivity were not significantly different in permeabilized smooth muscle of KO compared with wild-type (WT) mice, nor were the delays in onset and half-times of Ca2+ sensitization, initiated by flash photolysis of caged GTPgammaS, different. The unloaded shortening velocity (Vus) of thiophosphorylated fibres was significantly (P<0.05) faster in the smooth muscle of KO than WT animals, but could be slowed by exogenous calponin to approximate WT levels; the concentration dependence of exogenous calponin slowing of Vus was proportional to its actomyosin binding in situ. Actin expression was reduced by 25-50%, relative to that of myosin heavy chain, in smooth muscle of KO mice, without any change in the relative distribution of the actin isoforms. We conclude that the faster Vus of smooth muscle of the KO mouse is consistent with, but does not prove without further study, physiological regulation of the crossbridge cycle by calponin. Our results show no detectable role of calponin in the signal transduction of the Ca2+-sensitization pathways in smooth muscle.

Animals↗
PubMed1996

Effects of calponin on force generation by single smooth muscle cells.

Although the actin-binding and actomyosin adenosinetriphosphatase (ATPase) inhibitory properties of calponin are well documented in vitro, its function in the smooth muscle cell has not been elucidated. To address this question, we utilized the ferret aortic smooth muscle cell, which shows a protein kinase C-dependent contraction even at pCa (-log [Ca2+]) 9.0 in the absence of a change in myosin light chain phosphorylation. Force was recorded from single, briefly permeabilized cells stimulated via a Ca(2+)-independent pathway by either phenylephrine or the epsilon isoenzyme of protein kinase C. Treatment of stimulated cells with wild-type recombinant calponin reduced steady-state contractile force by 45-60%. When calponin application preceded protein kinase C epsilon treatment, contraction was completely suppressed. On the other hand, calponin phosphorylated at Ser175 or mutant calponin with a Ser175 --> Ala replacement had no effect on contractile force. A peptide corresponding to Leu166-Gly194 of calponin, which included an actin-binding domain but excluded the actomyosin ATPase inhibitory region, was synthesized. Treatment of aortic smooth muscle cells with this peptide triggered a concentration-dependent contraction, presumably by alleviating the inhibitory effect of endogenous calponin. A control peptide with a scrambled sequence of the same residues produced no detectable contractile response. Although other interpretations are possible, these results are consistent with the view that calponin participates in thin filament-mediated regulation of smooth muscle contraction and that it may be part of a Ca(2+)-independent pathway downstream of protein kinase C epsilon.

Animals↗
PubMed1996

Calcium-and phorbol ester-dependent calponin phosphorylation in homogenates of swine carotid artery.

Calponin inhibits actin-activated myosin adenosinetriphosphatase (ATPase) activity, and phosphorylation reverses this inhibition. Calponin phosphorylation has been demonstrated in reconstituted contractile protein systems, but studies using intact smooth muscle have produced mixed results. The goal of this study was to determine if vascular smooth muscle contains the necessary biochemical machinery to catalyze calponin phosphorylation. We used swine carotid homogenate, which allows access to the intracellular components and contains all endogenous proteins and enzymes in physiologically relevant concentrations. We demonstrated that calponin is phosphorylated in response to Ca2+ (0.27 +/- 0.04 mol P(i)/mol calponin) and in response to phorbol 12,13-dibutyrate in the presence or absence of Ca2+ (0.48 +/- 0.09 mol P(i)/mol calponin). Calponin phosphorylation was inhibited by the protein kinase C inhibitor staurosporine but not by the Ca(2+)- and calmodulin-dependent protein kinase II inhibitor KN-62. We conclude that Ca(2+)-dependent and -independent isoforms of protein kinase C but not the Ca(2+) -and calmodulin-dependent protein kinase II catalyze calponin phosphorylation in the swine carotid artery.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed2003

Role of H1-calponin in pancreatic AR42J cell differentiation into insulin-producing cells.

Basic or h1-calponin is a smooth muscle-specific, actin-binding protein that is involved in the regulation of smooth muscle contractile activity. We found in this study the expression of mRNA and protein for h1-calponin in AR42J-B13 cells, which is a useful model for investigating islet beta-cell differentiation from pancreatic common precursor cells. Following treatment of AR42J cells with activin A and hepatocyte growth factor, the protein levels of h1-calponin decreased in a time-dependent manner during the course of the cell differentiation. When h1-calponin was continuously overexpressed by utilizing recombinant adenovirus-mediated gene transfer, the percentage of cell differentiation in h1-calponin overexpressing cells was markedly suppressed as compared with that in the cells without overexpression (6.7 +/- 2.5 vs. 28.6 +/- 3.2%, P < 0.001, Student's t test). Finally, overexpression of h1-calponin (65.6 +/- 3.4), or that lacking actin-binding domain (55.9 +/- 3.4%), significantly (P < 0.001) suppressed the activin A-stimulated transcriptional activity of activin responsive element (ARE), whereas calponin homology-domain disruption mutant did not (100.6 +/- 1.9%). These results suggest that regulation of h1-calponin is involved in the regulation of differentiation of AR42J cells into insulin-producing cells at least partly through modulating ARE transcriptional activity.

Actins↗