CALM
Domain
The N-terminal and C-terminal lobes of CALM bind to the C-terminus of KCNQ1 in a clamp-like conformation. Binding of CALM C-terminus to KCNQ1 is calcium-independent but is essential for assembly of the structure. Binding of CALM N-terminus to KCNQ1 is calcium-dependent and regulates electrophysiological activity of the channel. The C-lobe interacts with KCNN4 channels in a calcium-independent manner, whereas the N-lobe interacts with the S4-S5 linker of KCNN4 in a calcium-dependent manner playing a role as calcium sensor and gating the channel.
Function
Calmodulin acts as part of a calcium signal transduction pathway by mediating the control of a large number of enzymes, ion channels, aquaporins and other proteins through calcium-binding. Calcium-binding is required for the activation of calmodulin. Among the enzymes to be stimulated by the calmodulin-calcium complex are a number of protein kinases, such as myosin light-chain kinases and calmodulin-dependent protein kinase type II (CaMK2), and phosphatases. Together with CCP110 and centrin, is involved in a genetic pathway that regulates the centrosome cycle and progression through cytokinesis. Is a regulator of voltage-dependent L-type calcium channels. Mediates calcium-dependent inactivation of CACNA1C. Positively regulates calcium-activated potassium channel activity of KCNN2. Forms a potassium channel complex with KCNQ1 and regulates electrophysiological activity of the channel via calcium-binding. Acts as a sensor to modulate the endoplasmic reticulum contacts with other organelles mediated by VMP1:ATP2A2.
Post-translational modifications
Ubiquitination results in a strongly decreased activity.
Phosphorylation results in a decreased activity.
Sequence Similarities
Belongs to the calmodulin family.
Cellular localization
- Cytoplasm
- Cytoplasm
- Cytoskeleton
- Spindle
- Cytoplasm
- Cytoskeleton
- Spindle pole
- Distributed throughout the cell during interphase, but during mitosis becomes dramatically localized to the spindle poles and the spindle microtubules.
Alternative names
CAM, CALM, Calmodulin, CaM