STIM1 (Stromal Interaction Molecule 1) is a key transmembrane protein involved in calcium (Ca²⁺) signaling, primarily acting as a Ca²⁺ sensor within the endoplasmic reticulum (ER). It plays a central role in store-operated calcium entry (SOCE), a process critical for maintaining intracellular Ca²⁺ homeostasis. When ER Ca²⁺ stores are depleted, STIM1 undergoes conformational changes, clusters at ER-plasma membrane junctions, and activates ORAI1 channels to mediate extracellular Ca²⁺ influx. This mechanism regulates diverse physiological processes, including immune cell activation, muscle contraction, and gene transcription.
STIM1 antibodies are essential tools for studying its expression, localization, and function in both normal and pathological contexts. These antibodies target specific epitopes of the STIM1 protein, enabling applications like Western blotting, immunofluorescence, flow cytometry, and immunoprecipitation. Researchers use them to investigate STIM1's role in diseases such as immunodeficiency syndromes, cardiovascular disorders, and cancers, where dysregulated Ca²⁺ signaling is implicated. For instance, STIM1 mutations or altered expression have been linked to tubular aggregate myopathy, thrombocytopenia, and tumor progression.
High-quality STIM1 antibodies are validated for specificity, often using knockout cell lines or tissues as controls. Commercial antibodies vary in host species, clonality (monoclonal/polyclonal), and conjugation formats, allowing flexibility in experimental design. Proper validation ensures reliable detection of STIM1's dynamic behavior during SOCE, aiding mechanistic studies of Ca²⁺-dependent cellular responses.