- Synthetic peptide mapping to an extracellular sequence of human Orai1 (Accession Q96D31).
- Cell surface detection of Orai1 in intact living Jurkat cells:___ Unstained cells.
___ Cells + Mouse Anti-Human Orai1 (extracellular)-ATTO Fluor-633 Antibody (#ALM-025-FR), (5 µg antibody/0.5-1 x 106 cells).
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Cytosolic calcium (Ca2+) has long been known to act as a key second messenger in many intracellular pathways including synaptic transmission, muscle contraction, hormonal secretion, cell growth and proliferation.1,2 The mechanism controlling intracellular Ca2+ level influx either by the calcium-release-activated Ca2+ channels (CRAC), or from intracellular stores, has become of great interest.
Recently, several key players of the store operated complex have been identified3. Orai1 (also known as CRACM1) acts as the store operated Ca2+ channel (SOC) and STIM1, which acts as the endoplasmic reticulum Ca2+ sensor3,4. The formation of functional channels requires the presence of both Orai1 and STIM1 proteins working as a complex and involves the co-clustering of Orai1 on the plasma membrane with STIM1 on the endoplasmic reticulum4-6. TRPC1, a member of the transient receptor potential family was also suggested to act as a player in the SOC complex7. In T-cells, Ca2+ entry following activation by antigen-receptor engagement occurs solely through CRAC channels where Orai1 constitutes the pore forming subunit3,8.
Orai1 is a plasma membrane protein with four potential transmembrane domains and intracellular N- and C-terminus. In addition, two mammalian homologs to Orai1 have been identified; Orai2 and Orai33,9. All three, Orai1 Orai2 and Orai3, are capable of forming store operated channels with different magnitudes9.
Species reactivity key:
Mouse Anti-Human Orai1 (extracellular) Antibody (#ALM-025) is a highly specific monoclonal antibody directed against an extracellular epitope of the human Orai1 channel. The antibody can be used in western blot, immunocytochemical and indirect flow cytometry applications and was designed to recognize Orai1 from human samples only.
Mouse Anti-Human Orai1 (extracellular)-ATTO Fluor-633 Antibody (#ALM-025-FR) is directly labeled with an ATTO-633 fluorescent dye. ATTO dyes are characterized by strong absorption (high extinction coefficient), high fluorescence quantum yield, and high photo-stability. ATTO 633 has a maximum absorption at 629 nm and a maximum fluorescence at 657 nm. The fluorescence is excited most efficiently in the range 610 to 645 nm. This label is analogous to the well-known dyes Alexa 647, Alexa 633 and Cy5. Mouse Anti-Human Orai1 (extracellular)-ATTO Fluor-633 Antibody is especially suited for experiments requiring simultaneous labeling of different markers.