Related Experiment Video

Updated: Jul 28, 2026

Pull-down of Calmodulin-binding Proteins
07:51

Pull-down of Calmodulin-binding Proteins

Published on: January 23, 2012

A role for calcium/calmodulin kinase in insulin stimulated glucose transport

D C Wright1, C A Fick, J B Olesen

  • 1Human Performance Laboratory, Ball State University, Muncie, IN 47306, USA. bcraig@bsu.edu

Life Sciences
|December 9, 2003
PubMed

Insights

Calcium/calmodulin dependent protein kinase (CAMK) signaling, not L-type calcium channels, appears to regulate insulin-stimulated glucose transport in skeletal muscle. Insulin increases CAMKII phosphorylation independently of calcium channels.

Area of Science:

  • * Molecular biology
  • * Cellular physiology
  • * Metabolic research

Background:

  • * Insulin stimulates glucose transport in skeletal muscle, a process crucial for glucose homeostasis.
  • * Calcium/calmodulin dependent protein kinase (CAMK) inhibitors reduce glucose transport, suggesting CAMK involvement.
  • * L-type calcium channels have been controversially implicated in insulin-stimulated glucose transport.

Purpose of the Study:

  • * To investigate if CAMK and L-type calcium channels share a common signaling pathway for insulin-stimulated glucose transport.
  • * To determine if insulin-induced CAMKII phosphorylation is dependent on L-type calcium channels.

Main Methods:

  • * Inhibition of insulin-stimulated glucose transport in rat soleus and epitrochlearis muscles using KN62 (CAMK inhibitor) and nifedipine (L-type calcium channel blocker).
  • * Measurement of insulin-induced CAMKII phosphorylation via Western blot analysis in rat soleus muscle.

Main Results:

  • * Both KN62 and nifedipine individually inhibited glucose transport by approximately 30%, with no additive effect when combined.
  • * Insulin significantly increased CAMKII phosphorylation by approximately 40% in soleus muscle.
  • * Insulin-induced CAMKII phosphorylation was blocked by KN62 but not by nifedipine.

Conclusions:

  • * CAMK signaling appears to regulate insulin-stimulated glucose transport in skeletal muscle.
  • * This CAMK mechanism operates independently of L-type calcium channels.
  • * L-type calcium channels are unlikely to be the primary mediators of insulin-induced CAMKII activation in this context.

More Related Videos

Imaging Calcium Dynamics in Subpopulations of Mouse Pancreatic Islet Cells08:03

Imaging Calcium Dynamics in Subpopulations of Mouse Pancreatic Islet Cells

Published on: November 26, 2019

Measurement of Insulin- and Contraction-Stimulated Glucose Uptake in Isolated and Incubated Mature Skeletal Muscle from Mice08:01

Measurement of Insulin- and Contraction-Stimulated Glucose Uptake in Isolated and Incubated Mature Skeletal Muscle from Mice

Published on: May 16, 2021

Related Concept Videos

Insulin Secretory Vesicles01:05

Insulin Secretory Vesicles

Insulin secretory vesicles release insulin to stimulate blood glucose uptake and regulate carbohydrate metabolism. When the blood glucose levels increase, glucose enters the pancreatic β-islet cells through glucose transporters. Once inside, glucose is metabolized through glycolysis, the citric acid cycle, and the electron transport chain, producing ATP. This increase in ATP concentration closes ATP-sensitive potassium channels, leading to depolarization of the membrane and the opening of...
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,...
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,...
Hormones Regulating Blood Glucose01:16

Hormones Regulating Blood Glucose

Insulin is released by beta cells of the pancreas when blood glucose levels are high. It facilitates glucose absorption and utilization in insulin-dependent cells with insulin receptors on their plasma membranes. Insulin promotes glucose uptake by increasing the number of glucose transport proteins in the cell membrane, allowing glucose to enter the cell. As a result, glucose utilization and ATP production are enhanced.
In addition to accelerating glucose uptake and utilization, insulin has...
Glucose Homeostasis: Pancreatic Islets and Insulin Secretion01:27

Glucose Homeostasis: Pancreatic Islets and Insulin Secretion

The pancreatic islets comprising only 1%-2% of the volume are highly vascularized and innervated mini-organs. They contain five endocrine cell types, including β cells that secrete insulin, which is synthesized as a single polypeptide chain, preproinsulin, processed to proinsulin, and finally to insulin and C-peptide. This process is complex and regulated, involving the Golgi complex, the endoplasmic reticulum, and the secretory granules of the β cell.
Insulin and C-peptide are co-secreted in...
Insulin: The Receptor and Signaling Pathways01:28

Insulin: The Receptor and Signaling Pathways

Insulin action is mediated through a receptor tyrosine kinase, akin to the IGF-1 receptor. The number of receptors per cell varies significantly, from 40 on erythrocytes to 300,000 on adipocytes and hepatocytes. The insulin receptor consists of linked α/β subunit dimers, forming a heterotetramer glycoprotein with two extracellular α subunits and two β subunits spanning the membrane. The α subunits inhibit the inherent tyrosine kinase activity of the β subunits, but this inhibition is released...