Calcium (Ca2+) signalling is a fundamental process that plays roles in a wide range of cellular functions, including cell proliferation, differentiation, apoptosis, synaptic transmission, and muscle contraction. Calcium ions are versatile intracellular messengers that regulate many physiological processes. The concentration of free calcium ions in the cytosol is usually maintained at very low levels, around 50-100 nM, compared to extracellular concentrations of approximately 1-2 mM. Calcium signals are highly dynamic, and they can be generated and propagated by various mechanisms, including voltage-gated calcium channels, ligand-gated receptors, and intracellular stores such as those in the endoplasmic reticulum. Extracellular calcium influx is mediated by several types of membrane calcium channels, including voltage-gated calcium channels (VGCCs) and receptor-operated calcium channels (ROCCs). VGCCs are activated by changes in the membrane potential, allowing calcium to enter the cell in response to depolarization. ROCCs, on the other hand, are activated by the binding of ligands, such as neurotransmitters or hormones, to specific receptors, leading to calcium influx. These mechanisms together ensure precise and regulated calcium entry into the cell. In addition to calcium entry, cells can also release calcium from intracellular stores, predominantly within the endoplasmic reticulum (ER). This process is mediated by inositol trisphosphate receptors (IP3Rs) and ryanodine receptors (RyRs), which are activated by second messengers such as IP3 and cyclic adenosine diphosphate ribose (cADPR). The release of calcium from the ER amplifies the calcium signal and enables spatial and temporal control over calcium-dependent processes. Once calcium ions are elevated in the cytosol, they bind to specific calcium-binding proteins, such as calmodulin (CaM), which act as calcium sensors and initiate downstream signalling events. Calcium/CaM complexes can activate a variety of effectors, including protein kinases, phosphatases, and transcription factors. These effectors modulate cellular processes by phosphorylating or dephosphorylating target proteins, altering their activity, localization, or gene expression. Calcium signalling is involved in a myriad of physiological processes. In neurons, it plays a crucial role in synaptic plasticity, neurotransmitter release, and neuronal excitability. In muscle cells, calcium signalling triggers contraction by promoting the interaction between actin and myosin filaments. Calcium also regulates cell proliferation, differentiation, and apoptosis through its influence on various signalling pathways, including those involving mitogen-activated protein kinases (MAPKs) and nuclear factor of activated T cells (NFAT). Furthermore, calcium signalling is essential for the proper functioning of the immune system, cardiovascular system, and endocrine system. Impairments in calcium signalling have been implicated in numerous pathological conditions, including neurodegenerative diseases, cardiovascular disorders, and cancer. Mutations in calcium channels or calcium-binding proteins can disrupt calcium homeostasis, leading to aberrant cellular responses and disease phenotypes. For example, in cystic fibrosis (CF) a genetic disorder that primarily affects the respiratory and digestive systems, mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) protein result in defective chloride ion transport, leading to altered calcium signalling in affected tissues. Disrupted calcium signalling in CF contributes to mucus build-up, impaired immune responses, and other manifestations of the disease. We offer a wide product range of research tools for studying calcium signaling, including Annexin A1 antibodies, E Cadherin antibodies, MARCKS antibodies, S100A11 ELISA Kits, and MEF2A+MEF2C ELISA Kits. Explore our full calcium signaling product range below and discover more, for less. Alternatively, you can explore our Calcium Binding Proteins, Calmodulin Pathway, and Calcium Channels product ranges.