1. Re-evaluation of the role of calcium homeostasis endoplasmic reticulum protein (CHERP) in cellular calcium signaling.
- Author
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Lin-Moshier Y, Sebastian PJ, Higgins L, Sampson ND, Hewitt JE, and Marchant JS
- Subjects
- Amino Acid Sequence, Calcium Signaling, Cell Cycle, Cell Membrane metabolism, Cytoplasm metabolism, Endoplasmic Reticulum metabolism, HEK293 Cells, Homeostasis, Humans, Inositol 1,4,5-Trisphosphate Receptors metabolism, Jurkat Cells, Molecular Sequence Data, Mutation, RNA Interference, Ribonucleoproteins chemistry, Ryanodine Receptor Calcium Release Channel metabolism, Spliceosomes metabolism, Subcellular Fractions metabolism, Calcium metabolism, DNA-Binding Proteins metabolism, Gene Expression Regulation, Membrane Proteins metabolism, Nucleosomes metabolism, RNA-Binding Proteins metabolism, Ribonucleoproteins metabolism
- Abstract
Changes in cytoplasmic Ca(2+) concentration, resulting from activation of intracellular Ca(2+) channels within the endoplasmic reticulum, regulate several aspects of cellular growth and differentiation. Ca(2+) homeostasis endoplasmic reticulum protein (CHERP) is a ubiquitously expressed protein that has been proposed as a regulator of both major families of endoplasmic reticulum Ca(2+) channels, inositol 1,4,5-trisphosphate receptors (IP(3)Rs) and ryanodine receptors (RyRs), with resulting effects on mitotic cycling. However, the manner by which CHERP regulates intracellular Ca(2+) channels to impact cellular growth is unknown. Here, we challenge previous findings that CHERP acts as a direct cytoplasmic regulator of IP(3)Rs and RyRs and propose that CHERP acts in the nucleus to impact cellular proliferation by regulating the function of the U2 snRNA spliceosomal complex. The previously reported effects of CHERP on cellular growth therefore are likely indirect effects of altered spliceosomal function, consistent with prior data showing that loss of function of U2 snRNP components can interfere with cell growth and induce cell cycle arrest.
- Published
- 2013
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