Related Experiment Video
Updated: Jul 5, 2026

Pull-down of Calmodulin-binding Proteins
Published on: January 23, 2012
Calmodulin binding to the polybasic C-termini of STIM proteins involved in store-operated calcium entry
Mikael C Bauer1, David O'Connell, Dolores J Cahill
1Lund University, Biophysical Chemistry, Chemical Centre, P O Box 124, SE221 00 Lund, Sweden.
Abstract:
Translocation of STIM1 and STIM2 from the endoplasmic reticulum to the plasma membrane is a key step in store-operated calcium entry in the cell. We show by isothermal titration calorimetry that calmodulin binds in a calcium-dependent manner to the polybasic C-termini of STIM1 and STIM2, a region critical for their translocation to the plasma membrane ( K D < or = 1 microM in calcium). HSQC NMR spectroscopy shows this interaction is in the fast exchange regime. By binding STIM1 and STIM2, calmodulin may regulate store refilling, thereby ensuring the maintenance of its own action in intracellular signaling.
Related Concept Videos
Calmodulin-dependent Signaling
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 Concentration
Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs...
Smooth Muscle Contraction
The onset of contraction is triggered by an increase in calcium ions within the sarcoplasm, similar to the process in striated muscle. However, smooth muscles have a relatively smaller reservoir of the sarcoplasmic...
Ligand-Gated Ion Channel Receptor: Gating Mechanism
Amplifying Signals via Second Messengers
Antihypertensive Drugs: Action of Calcium Channel Blockers

