Overview
- Peptide CHSEDEKLSFEAVR, corresponding to amino acid residues 56-69 of human STIM1 (Accession Q13586). STIM1 expressed on the plasma membrane: Extracellular, N-terminus. STIM1 expressed on the ER: Luminal, N-terminus.
- Expression of STIM1 in rat pancreasImmunohistochemical staining of rat paraffin-embedded pancreas sections using Anti-STIM1 (extracellular)-ATTO Fluor-550 Antibody (#ACC-063-AO), (1:20), (red). A. STIM1 staining is highly specific for endocrine cells in the Isle of Langerhans. B. Hoechst 33342 (blue) is used as the counterstain. C. Merged image of panels A and B.
- Cell surface detection of STIM1 in human Jurkat T-cell leukemia cells:___ Cells.
___ Cells + rabbit IgG isotype control-ATTO Fluro-550 (#RIC-001-AO).
___ Cells + Anti-STIM1 (extracellular)-ATTO Fluor-550 Antibody (#ACC-063-AO), (5 µg). - Cell surface detection of STIM1 in rat basophilic leukemia (RBL) cell lysate:___ Cells.
___ Cells + rabbit IgG isotype control-ATTO Fluro-550 (#RIC-001-AO).
___ Cells + Anti-STIM1 (extracellular)-ATTO Fluor-550 Antibody (#ACC-063-AO), (5 µg).
- Expression of STIM1 in RBL cellsCell surface detection of STIM1 in live RBL cells. A. Extracellular staining of cells with Anti-STIM1 (extracellular)-ATTO Fluor-550 Antibody (#ACC-063-AO), (1:20). B. Nuclear staining of cells using the cell-permeable dye Hoechst 33342. C. Merged image of panels A and B.
- Eisner, D.A. et al. (2005) Exp. Physiol. 90, 3.
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Cytosolic Ca2+ has long been known to act as a key second messenger in many intracellular pathways including synaptic transmission, muscle contraction, hormonal secretion, and cell growth and proliferation.1,2 The mechanism controlling the influx of intracellular Ca2+ either by calcium-release-activated Ca2+ channels (CRAC) or from intracellular stores has lately become of great interest.
Recently, several key players of the store-operated complex have been identified.3 The Orai family consists of three members, Orai1-3, and the STIM family, which consists of two members, STIM1 and STIM2. Orai1 (also known as CRACM1) acts as the store-operated calcium channel (SOC) and STIM1 as the endoplasmic reticulum (ER) Ca2+ sensor.3,4 The majority of STIM1 appears to be localized intracellularly at the ER membrane while low expression of STIM1 has been detected on the cell surface of several cell types.5 STIM1 has an amino-terminal EF hand Ca2+ binding domain facing the lumen of the ER.6 Upon Ca2+ store depletion, STIM1 molecules are redistributed in punctae underneath the plasma membrane and activate SOCs.
Several possible interactions between STIM1 and Orai1 have been suggested. The most simple and cited is a dynamic interaction between the cytosolic C-terminus of STIM1 and the cytoplasmic domain of the Orai1 channel.7-9 STIM1 is assumed to regulate the activity of all known SOCs, including native SOCs.5 Consistent with their important role as calcium sensors within the ER, STIM1 proteins are ubiquitously expressed.
Application key:
Species reactivity key:
Anti-STIM1 (extracellular) Antibody (#ACC-063) is a highly specific antibody directed against an extracellular epitope of the human Stromal interaction molecule 1. The antibody can be used in western blot, immunocytochemistry, immunohistochemistry, and indirect flow cytometry applications. It has been designed to recognize STIM1 from human, rat, and mouse samples.
Anti-STIM1 (extracellular)-ATTO Fluor-550 Antibody (#ACC-063-AO) is directly labeled with an ATTO-550 fluorescent dye. ATTO dyes are characterized by strong absorption (high extinction coefficient), high fluorescence quantum yield, and high photo-stability. The ATTO-550 fluorescent label is related to the well known dye Rhodamine 6G and can be used with filters typically used to detect Rhodamine. Anti-STIM1 (extracellular)-ATTO Fluor-550 Antibody has been tested in immunocytochemistry and immunohistochemistry applications and is especially suited for experiments requiring simultaneous labeling of different markers.
Applications
Citations
- Mouse NSC-34 motor neuron cells (1:200).
Tedeschi V. et al. (2019) Sci Rep. 9, 10743.