Related Experiment Video

Updated: Jul 10, 2026

Monitoring Dynamic Changes In Mitochondrial Calcium Levels During Apoptosis Using A Genetically Encoded Calcium Sensor
06:26

Monitoring Dynamic Changes In Mitochondrial Calcium Levels During Apoptosis Using A Genetically Encoded Calcium Sensor

Published on: April 1, 2011

Stringent time-dependent transregulation of calcium calmodulin kinase II (CaMKII) is implicated in anti-apoptotic

Michael Fährmann1, Sarah Honisch, Marc-André Kaufhold

  • 1Medizinische Hochschule Hannover, Institut für Pharmakologie OE 5320, Carl-Neuberg-Str. 1, D-30625 Hannover, Germany. faehrmann.michael@mh-hannover.de

Biochimica Et Biophysica Acta
|November 13, 2007
PubMed

Insights

Calcineurin-like protein phosphatase (PP1/PP2A) inhibitor calyculin A induces apoptosis by hyperphosphorylating Ca2+/calmodulin-dependent protein kinase II (CaMKII). This process is blocked by CaMKII inhibitor KN-93, suggesting CaMKII

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Biochemistry

Background:

  • The role of Ca2+/calmodulin-dependent protein kinase II (CaMKII) in apoptosis is not fully understood.
  • Calcineurin-like protein phosphatase (PP1/PP2A) inhibitors, like calyculin A, can induce apoptosis.

Purpose of the Study:

  • To investigate the physiological relevance and mechanism of CaMKII during apoptosis.
  • To elucidate the role of CaMKII transregulation in controlling its autophosphorylation kinetics.
  • To determine if calyculin A-induced hyperphosphorylation of CaMKII triggers apoptosis.

Main Methods:

  • Using MDCK and gastric parietal cells to study CaMKII kinetics.
  • Investigating CaMKII transregulation by phosphatases (PP1, PP2A, PP2B) and PKCalpha.
  • Analyzing CaMKII autophosphorylation at T286/287 using in vivo and in vitro methods.
  • Assessing the effect of calyculin A on CaMKII phosphorylation and apoptosis induction.

Main Results:

  • Normal CaMKII transregulation limits autophosphorylation to an initial 10-minute burst.
  • CaMKII exhibits two kinetic phases for T286/287 phosphorylation: a peak followed by a sustained lower level.
  • Calyculin A disrupts transregulation, leading to CaMKII hyperphosphorylation.
  • Calyculin A-induced CaMKII hyperphosphorylation was observed in intact cells and isolated tubulovesicles.

Conclusions:

  • Calyculin A-induced CaMKII hyperphosphorylation is a mechanism triggering apoptosis.
  • Strict regulation of CaMKII autophosphorylation by transregulation prevents hyperphosphorylation and restricts apoptosis.
  • Understanding CaMKII regulation offers insights into apoptosis pathways.

More Related Videos

Live Cell Calcium Imaging Combined with siRNA Mediated Gene Silencing Identifies Ca2+ Leak Channels in the ER Membrane and their Regulatory Mechanisms13:40

Live Cell Calcium Imaging Combined with siRNA Mediated Gene Silencing Identifies Ca2+ Leak Channels in the ER Membrane and their Regulatory Mechanisms

Published on: July 7, 2011

Pull-down of Calmodulin-binding Proteins07:51

Pull-down of Calmodulin-binding Proteins

Published on: January 23, 2012

Related Concept Videos

Calmodulin-dependent Signaling01:16

Calmodulin-dependent Signaling

Calmodulin (CaM) is a calcium-binding protein in eukaryotes that controls various calcium-regulated cellular processes. It has four calcium-binding sites that bind calcium to form the calcium-calmodulin ( Ca2+-CaM) complex. GPCR stimulation increases the calcium levels in the cells that bind to CaM and induces a conformational change.
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
Feedback Regulation of Calcium Concentration01:27

Feedback Regulation of Calcium Concentration

Calcium is an essential signaling molecule required for various cellular functions. Calcium pumps and ion channels on cell and organellar membranes, such as those on the endoplasmic reticulum (ER), regulate calcium concentrations inside the cell. They remain closed, keeping the cytosolic calcium levels low at a resting state.
Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs...
The Extrinsic Apoptotic Pathway01:17

The Extrinsic Apoptotic Pathway

The extrinsic apoptotic pathway is initiated when extracellular death-inducing signals, such as specific cytokines, activate the death receptors expressed on the cell surface. The immune cells involved in this pathway are natural killer cells (NK cells) and cytotoxic T-lymphocytes. NK cells are critical in innate immune response, while cytotoxic T-lymphocytes are associated with adaptive immune response. These cells recognize specific receptors expressed on the altered cells and activate...
cAMP-dependent Protein Kinase Pathways01:25

cAMP-dependent Protein Kinase Pathways

Cyclic Adenosine Monophosphate (cAMP) is an essential second messenger that activates protein kinase A (PKA) and regulates various biological processes. A single epinephrine molecule binds to GPCR and activates several heterotrimeric G proteins, each stimulating multiple adenylyl cyclase, amplifying the signal, and synthesizing large numbers of cAMP molecules. Small changes in cAMP concentration affect PKA activity. The binding of four cAMP molecules induces a conformational change in PKA,...
Caspases01:24

Caspases

Caspase, a family of cysteine proteases, serve as effectors in apoptosis. The ced3 gene in C.elegans was first identified to be involved in apoptosis. This gene encodes the ced-3 caspase that is similar to the interleukin-1-beta converting enzyme or ICE in mammals. In addition to apoptosis, caspases also function in the inflammatory response. Inflammatory caspases are essential in activating pro-inflammatory cytokines that recruit immune cells and block the replication of pathogens inside cells.
The Intrinsic Apoptotic Pathway01:31

The Intrinsic Apoptotic Pathway

Internal cellular stress, such as cellular injury or hypoxia, triggers intrinsic apoptosis. The B-cell lymphoma 2 (Bcl-2) family of proteins are the primary regulators of the intrinsic apoptotic pathway. For example, during DNA damage, checkpoint proteins, such as Ataxia Telangiectasia Mutated (ATM protein) and Checkpoints Factor-2 (Chk2) proteins, are activated. These proteins phosphorylate p53 which further activates pro-apoptotic proteins, such as Bax, Bak, PUMA, and Noxa, and inhibits...