title: Alternative forms of the store-operated calcium entry mediators, STIM1 and Orai1.
abstract: Activation of phospholipase C results in release of intracellular Ca(2+) and activation of Ca(2+) entry. Plasma membrane Ca(2+) entry most commonly is signaled by the depletion of intracellular Ca(2+) stores, a mechanism referred to as capacitative calcium entry or store-operated calcium entry (SOCE). The major players in the SOCE pathway are a Ca(2+) sensor protein, STIM1, and a channel subunit, Orai1. STIM1 activates Orai channels by a mechanism that depends upon its colocalization with Orai at endoplasmic reticulum-plasma membrane junctions. Signaling proteins often occur in multiple forms with distinct properties and/or functions. Such forms arise by a number of mechanisms, including covalent modification, alternative splicing, and alternative translation initiation. This chapter summarizes and discusses recent work revealing alternative forms of STIM1 and Orai1, and the physiological consequences of these modified proteins.
authors.affiliation: Laboratory of Signal Transduction, National Institute of Environmental Health Sciences-NIH, Department of Health and Human Services, Durham, North Carolina, USA. putney@niehs.nih.gov
authors.forename: James W
authors.initials: JW
authors.lastname: Putney
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015220:Calcium Channels / Q000378:metabolism*; D020013:Calcium Signaling; D004721:Endoplasmic Reticulum / Q000378:metabolism; D006801:Humans; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism*; D008938:Mitosis; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000737:chemistry / Q000378:metabolism*; D000071740:ORAI1 Protein; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational; D017434:Protein Structure, Tertiary; D000071737:Stromal Interaction Molecule 1
chemical_list: D015220:Calcium Channels; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D000071740:ORAI1 Protein; C510746:ORAI1 protein, human; C103530:STIM1 protein, human; D000071737:Stromal Interaction Molecule 1
keywords: Alternative translation initiation; Fluorescence recovery after photobleaching; Microtubules; Mitosis; Orai1; STIM1; Store-operated calcium entry