Activation of calcium and calmodulin dependent protein kinase II during stimulation of insulin secretion

Norling, Laura L.; Colca, Jerry R.; McDaniel, Michael L.; Landt, Michael

doi:10.1016/0143-4160(94)90008-6

Cited by 23 publications

(19 citation statements)

References 45 publications

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“…RyR is thought to be a Ca 2ϩ channel for cADPR as an endogenous activator, and phosphorylation and activation of RyR by CaM kinase II were reported (25)(26)(27). Furthermore, in islets, CaM kinase II was observed to be activated by glucose stimulation (28,29). Therefore, as depicted in Fig.…”

Section: Activation Of Cadpr-mediated Camentioning

confidence: 85%

“…Glucose stimulation induces cADPR accumulation in islets, and cADPR acts on RyR as a second messenger for intracellular Ca 2ϩ mobilization (4 -6, 21, 23, 24). On the other hand, CaM kinase II is activated by glucose stimulation (28,29), and the activated kinase phosphorylates RyR to sensitize the Ca 2ϩ channel for the cADPR signal. Pi, phosphorylation of RyR by CaM kinase II.…”

Section: Fig 4 Model For Cadpr-induced Camentioning

confidence: 99%

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Requirement of Calmodulindependent Protein Kinase II in Cyclic ADP-ribose-mediated Intracellular Ca2+ Mobilization

Takasawa

Ishida

Nata

et al. 1995

Journal of Biological Chemistry

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Cyclic ADP-ribose (cADPR) is generated in pancreatic islets by glucose stimulation, serving as a second messenger for Ca 2؉ mobilization from the endoplasmic reticulum for insulin secretion (Takasawa, S., Nata, K., Yonekura, H., and Okamoto, H. (1993) Science 259, 370 -373). In the present study, we observed that the addition of calmodulin (CaM) to rat islet microsomes sensitized and activated the cADPR-mediated Ca 2؉ release. Inhibitors for CaM-dependent protein kinase II (CaM kinase II) completely abolished the glucose-induced insulin secretion as well as the cADPR-mediated and CaM-activated Ca 2؉ mobilization. Western blot analysis revealed that the microsomes contain the ␣ isoform of CaM kinase II but do not contain CaM. When the active 30-kDa chymotryptic fragment of CaM kinase II was added to the microsomes, fully activated cADPR-mediated Ca 2؉ release was observed in the absence of CaM. These results along with available evidence strongly suggest that CaM kinase II is required to phosphorylate and activate the ryanodine-like receptor, a Ca 2؉ channel for cADPR as an endogenous activator, for the cADPR-mediated Ca 2؉ release.

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Section: Activation Of Cadpr-mediated Camentioning

confidence: 85%

Section: Fig 4 Model For Cadpr-induced Camentioning

confidence: 99%

Requirement of Calmodulindependent Protein Kinase II in Cyclic ADP-ribose-mediated Intracellular Ca2+ Mobilization

Takasawa

Ishida

Nata

et al. 1995

Journal of Biological Chemistry

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“…Taken together, these findings demonstrate that the usual complement of ion channels are present in the CaM beta cell and are functional. While there is some evidence that CaM-regulated pathways may modulate ion channels in beta cells (24,25), the 5-fold overexpression of CaM in these beta cells (1) appears to have no direct effects on the ion channels.…”

Section: Discussionmentioning

confidence: 99%

Defective Glycolysis and Calcium Signaling Underlie Impaired Insulin Secretion in a Transgenic Mouse

Ribar

Jan

Augustine

et al. 1995

Journal of Biological Chemistry

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] i transients to near normal levels. Electrophysiological analysis of the beta cell ion channels revealed that Ca 2؉ currents, delayed rectifier K ؉ currents, and K ؉ ATP channel currents were similar in transgenic and nontransgenic cells, suggesting that these ion channels were able to function normally. However, whereas K ؉ ATP channel currents in control cells were reduced by 50% by the presence of high glucose, those in transgenic cells were unaltered. Addition of tolbutamide inhibited this channel and enhanced the secretion of insulin in response to glucose for both control and transgenic cells. As these observations implicated a metabolic defect, glucose utilization, which is an indicator of glucose metabolism and ATP production in beta cells, was measured and found to be reduced by 40% in the transgenic cells. These data support the contention that excessive levels of calmodulin may compromise the ability of the beta cell to metabolize glucose and to modulate the state of the K ؉ ATP channel, resulting in an inadequate control of the membrane potential, which collectively impair [Ca 2؉ ] i and thus insulin secretion in response to glucose.

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“…Studies in intact cells indicate that autophosphorylation accompanies physiological activation and autophosphorylation renders the kinase constitutively active [14,15]. Therefore, CaM kinase autophosphorylation and the generation of autonomous activity are used as a marker for CaM kinase activation in intact cells, in response to extracellular signals or during a cellular response [15][16][17].…”

Section: Introductionmentioning

confidence: 99%

The endogenous cardiac sarcoplasmic reticulum Ca²⁺/calmodulin‐dependent kinase is activated in response to β‐adrenergic stimulation and becomes Ca²⁺‐independent in intact beating hearts

et al. 1997

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We investigated the effects of ß-adrenergic stimulation on the activity of the endogenous cardiac sarcoplasmic reticulum Ca 2+ /calmodulin-dependent protein kinase (SRCaM kinase) in Langendorff-perfused rat hearts. We found that isoproterenol induced generation of autonomous (Ca 2+ -independent) SRCaM kinase activity to 28 ± 4.4% of the total activity. Moreover, dephosphorylation of the autonomous SRCaM kinase with protein phosphatase 2A resulted in an enzyme that was again dependent on Ca 2+ and calmodulin for its activity. Activation of SRCaM kinase was coupled to phospholamban phosphorylation and activation of the cAMP-signaling system. Our results suggest that the cardiac SRCaM kinase is activated in response to /3-adrenoceptor stimulation. This activation stimulates autophosphorylation at its regulatory domain and converts it to an active Ca 2+ -independent species that may be the basis for potentiation of Ca 2+ transients in the heart.

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Activation of calcium and calmodulin dependent protein kinase II during stimulation of insulin secretion

Cited by 23 publications

References 45 publications

Requirement of Calmodulindependent Protein Kinase II in Cyclic ADP-ribose-mediated Intracellular Ca2+ Mobilization

Requirement of Calmodulindependent Protein Kinase II in Cyclic ADP-ribose-mediated Intracellular Ca2+ Mobilization

Defective Glycolysis and Calcium Signaling Underlie Impaired Insulin Secretion in a Transgenic Mouse

The endogenous cardiac sarcoplasmic reticulum Ca²⁺/calmodulin‐dependent kinase is activated in response to β‐adrenergic stimulation and becomes Ca²⁺‐independent in intact beating hearts

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Activation of calcium and calmodulin dependent protein kinase II during stimulation of insulin secretion

Cited by 23 publications

References 45 publications

Requirement of Calmodulindependent Protein Kinase II in Cyclic ADP-ribose-mediated Intracellular Ca2+ Mobilization

Requirement of Calmodulindependent Protein Kinase II in Cyclic ADP-ribose-mediated Intracellular Ca2+ Mobilization

Defective Glycolysis and Calcium Signaling Underlie Impaired Insulin Secretion in a Transgenic Mouse

The endogenous cardiac sarcoplasmic reticulum Ca2+/calmodulin‐dependent kinase is activated in response to β‐adrenergic stimulation and becomes Ca2+‐independent in intact beating hearts

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The endogenous cardiac sarcoplasmic reticulum Ca²⁺/calmodulin‐dependent kinase is activated in response to β‐adrenergic stimulation and becomes Ca²⁺‐independent in intact beating hearts