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Cardiac myosin binding protein C phosphorylation in cardiac disease.

Kuster DW, Bawazeer AC, Zaremba R, Goebel M, Boontje NM, van der Velden J - J. Muscle Res. Cell. Motil. (2011)

Bottom Line: Perturbations in sarcomeric function may in part underlie systolic and diastolic dysfunction of the failing heart.Sarcomeric dysfunction has been ascribed to changes in phosphorylation status of sarcomeric proteins caused by an altered balance between intracellular kinases and phosphatases during the development of cardiac disease.In the present review we discuss changes in phosphorylation of the thick filament protein myosin binding protein C (cMyBP-C) reported in failing myocardium, with emphasis on phosphorylation changes observed in familial hypertrophic cardiomyopathy caused by mutations in MYBPC3.

View Article: PubMed Central - PubMed

Affiliation: Department of Physiology, VU University Medical Center, Amsterdam, The Netherlands. d.kuster@vumc.nl

ABSTRACT
Perturbations in sarcomeric function may in part underlie systolic and diastolic dysfunction of the failing heart. Sarcomeric dysfunction has been ascribed to changes in phosphorylation status of sarcomeric proteins caused by an altered balance between intracellular kinases and phosphatases during the development of cardiac disease. In the present review we discuss changes in phosphorylation of the thick filament protein myosin binding protein C (cMyBP-C) reported in failing myocardium, with emphasis on phosphorylation changes observed in familial hypertrophic cardiomyopathy caused by mutations in MYBPC3. Moreover, we will discuss assays which allow to distinguish between functional consequences of mutant sarcomeric proteins and (mal)adaptive changes in sarcomeric protein phosphorylation.

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PKA-mediated cMyBP-C phosphorylation in vitro and in vivo. a 2D-gel analysis of cMYBP-C from IDCM myocardium before and after PKA treatment, showing an shift towards lower pI species, indicating increased phosphorylation. b Quantification of the changes in phosphorylation after PKA treatment. c, d Effect of high and low dose Dob administration (2 and 10 μg/kg/min; Dob2 and Dob10) on the phosphorylation of the PKA-specific Ser23/24 cTnI site (n = 5) and Ser282 cMyBP-C site (n = 6) in sham and post-MI remodeled myocardium from pigs. cTnI phosphorylation increased significantly in sham animals but this increase was attenuated in MI animals. cMyBP-C was not different between MI and sham animals. Figure adapted from Boontje et al. (2011) with permission from Elsevier. *P < 0.05, effect of Dob in a 1-way ANOVA
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Fig3: PKA-mediated cMyBP-C phosphorylation in vitro and in vivo. a 2D-gel analysis of cMYBP-C from IDCM myocardium before and after PKA treatment, showing an shift towards lower pI species, indicating increased phosphorylation. b Quantification of the changes in phosphorylation after PKA treatment. c, d Effect of high and low dose Dob administration (2 and 10 μg/kg/min; Dob2 and Dob10) on the phosphorylation of the PKA-specific Ser23/24 cTnI site (n = 5) and Ser282 cMyBP-C site (n = 6) in sham and post-MI remodeled myocardium from pigs. cTnI phosphorylation increased significantly in sham animals but this increase was attenuated in MI animals. cMyBP-C was not different between MI and sham animals. Figure adapted from Boontje et al. (2011) with permission from Elsevier. *P < 0.05, effect of Dob in a 1-way ANOVA

Mentions: To establish which kinases are responsible for cMyBP-C phosphorylation, both in vivo and in vitro studies have been used. The first clue that PKA could phosphorylate cMyBP-C was the observation that phosphorylation of cMyBP-C was increased after beta-adrenergic receptor stimulation in rat hearts (Jeacocke and England 1980) and frog atria (Hartzell and Titus 1982). In a follow-up study it was shown that PKA could phosphorylate isolated cMyBP-C in vitro (Hartzell and Glass 1984). In agreement, PKA incubation of skinned cardiomyocytes from end-stage failing heart tissue showed a shift towards cMyBP-C forms with a lower iso-electric point (increased pH) on 2D gel electrophoresis, indicating increased phosphorylation (Fig. 3a, b). In vitro phosphorylation of isolated cMyBP-C by PKA in the presence of [32P] ATP, followed by proteolysis and sequencing could pinpoint the three phosphorylation sites to the cardio-specific region between the C1 and C2 domains of the protein (Gautel et al. 1995; Mohamed et al. 1998). Functionally it was found that phosphorylation of cMyBP-C with PKA lead to changes in thick filament structure and an increased level of weakly bound cross-bridges at low Ca2+-levels, which could lead to increased force generating cross-bridges during systole (Levine et al. 2001).Fig. 3


Cardiac myosin binding protein C phosphorylation in cardiac disease.

Kuster DW, Bawazeer AC, Zaremba R, Goebel M, Boontje NM, van der Velden J - J. Muscle Res. Cell. Motil. (2011)

PKA-mediated cMyBP-C phosphorylation in vitro and in vivo. a 2D-gel analysis of cMYBP-C from IDCM myocardium before and after PKA treatment, showing an shift towards lower pI species, indicating increased phosphorylation. b Quantification of the changes in phosphorylation after PKA treatment. c, d Effect of high and low dose Dob administration (2 and 10 μg/kg/min; Dob2 and Dob10) on the phosphorylation of the PKA-specific Ser23/24 cTnI site (n = 5) and Ser282 cMyBP-C site (n = 6) in sham and post-MI remodeled myocardium from pigs. cTnI phosphorylation increased significantly in sham animals but this increase was attenuated in MI animals. cMyBP-C was not different between MI and sham animals. Figure adapted from Boontje et al. (2011) with permission from Elsevier. *P < 0.05, effect of Dob in a 1-way ANOVA
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3351594&req=5

Fig3: PKA-mediated cMyBP-C phosphorylation in vitro and in vivo. a 2D-gel analysis of cMYBP-C from IDCM myocardium before and after PKA treatment, showing an shift towards lower pI species, indicating increased phosphorylation. b Quantification of the changes in phosphorylation after PKA treatment. c, d Effect of high and low dose Dob administration (2 and 10 μg/kg/min; Dob2 and Dob10) on the phosphorylation of the PKA-specific Ser23/24 cTnI site (n = 5) and Ser282 cMyBP-C site (n = 6) in sham and post-MI remodeled myocardium from pigs. cTnI phosphorylation increased significantly in sham animals but this increase was attenuated in MI animals. cMyBP-C was not different between MI and sham animals. Figure adapted from Boontje et al. (2011) with permission from Elsevier. *P < 0.05, effect of Dob in a 1-way ANOVA
Mentions: To establish which kinases are responsible for cMyBP-C phosphorylation, both in vivo and in vitro studies have been used. The first clue that PKA could phosphorylate cMyBP-C was the observation that phosphorylation of cMyBP-C was increased after beta-adrenergic receptor stimulation in rat hearts (Jeacocke and England 1980) and frog atria (Hartzell and Titus 1982). In a follow-up study it was shown that PKA could phosphorylate isolated cMyBP-C in vitro (Hartzell and Glass 1984). In agreement, PKA incubation of skinned cardiomyocytes from end-stage failing heart tissue showed a shift towards cMyBP-C forms with a lower iso-electric point (increased pH) on 2D gel electrophoresis, indicating increased phosphorylation (Fig. 3a, b). In vitro phosphorylation of isolated cMyBP-C by PKA in the presence of [32P] ATP, followed by proteolysis and sequencing could pinpoint the three phosphorylation sites to the cardio-specific region between the C1 and C2 domains of the protein (Gautel et al. 1995; Mohamed et al. 1998). Functionally it was found that phosphorylation of cMyBP-C with PKA lead to changes in thick filament structure and an increased level of weakly bound cross-bridges at low Ca2+-levels, which could lead to increased force generating cross-bridges during systole (Levine et al. 2001).Fig. 3

Bottom Line: Perturbations in sarcomeric function may in part underlie systolic and diastolic dysfunction of the failing heart.Sarcomeric dysfunction has been ascribed to changes in phosphorylation status of sarcomeric proteins caused by an altered balance between intracellular kinases and phosphatases during the development of cardiac disease.In the present review we discuss changes in phosphorylation of the thick filament protein myosin binding protein C (cMyBP-C) reported in failing myocardium, with emphasis on phosphorylation changes observed in familial hypertrophic cardiomyopathy caused by mutations in MYBPC3.

View Article: PubMed Central - PubMed

Affiliation: Department of Physiology, VU University Medical Center, Amsterdam, The Netherlands. d.kuster@vumc.nl

ABSTRACT
Perturbations in sarcomeric function may in part underlie systolic and diastolic dysfunction of the failing heart. Sarcomeric dysfunction has been ascribed to changes in phosphorylation status of sarcomeric proteins caused by an altered balance between intracellular kinases and phosphatases during the development of cardiac disease. In the present review we discuss changes in phosphorylation of the thick filament protein myosin binding protein C (cMyBP-C) reported in failing myocardium, with emphasis on phosphorylation changes observed in familial hypertrophic cardiomyopathy caused by mutations in MYBPC3. Moreover, we will discuss assays which allow to distinguish between functional consequences of mutant sarcomeric proteins and (mal)adaptive changes in sarcomeric protein phosphorylation.

Show MeSH
Related in: MedlinePlus