Molecular cloning and characterization of SCaMPER, a sphingolipid Ca2+ release-mediating protein from endoplasmic reticulum
| Autor: | S. H. Kim, L. A. Kindman, D. M. Kearney, X. L. Rudner, Cungui Mao, J. S. Almenoff |
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| Rok vydání: | 1996 |
| Předmět: |
DNA
Complementary Molecular Sequence Data Xenopus Endoplasmic Reticulum Protein Structure Secondary Xenopus laevis Dogs Animals Amino Acid Sequence Cloning Molecular Cells Cultured Sphingolipids Multidisciplinary Membrane Glycoproteins biology Voltage-dependent calcium channel Base Sequence Ryanodine receptor Endoplasmic reticulum Translation (biology) biology.organism_classification Cell biology Biochemistry Microsome Calcium Calcium Channels Signal transduction Ion Channel Gating Intracellular Research Article |
| Zdroj: | Proceedings of the National Academy of Sciences of the United States of America. 93(5) |
| ISSN: | 0027-8424 |
| Popis: | Release of Ca2+ stored in endoplasmic reticulum is a ubiquitous mechanism involved in cellular signal transduction, proliferation, and apoptosis. Recently, sphingolipid metabolites have been recognized as mediators of intracellular Ca2+ release, through their action at a previously undescribed intracellular Ca2+ channel. Here we describe the molecular cloning and characterization of a protein that causes the expression of sphingosyl-phosphocholine-mediated Ca2+ release when its complementary RNA is injected into Xenopus oocytes. SCaMPER (for sphingolipid Ca2+ release-mediating protein of endoplasmic reticulum) is an 181 amino acid protein with two putative membrane-spanning domains. SCaMPER is incorporated into microsomes upon expression in SO cells or after translation in vitro. It mediates Ca2+ release at 4 degrees C as well as 22 degrees C, consistent with having ion channel function. The EC50 for Ca2+ release from Xenopus oocytes is 40 microM, similar to sphingosyl-phosphocholine-mediated Ca2+ release from permeabilized mammalian cells. Because Ca2+ release is not blocked by ryanodine or La3+, the activity described here is distinct from the Ca2+ release activity of the ryanodine receptor and the inositol 1,4,5-trisphosphate receptor. The properties of SCaMPER are identical to those of the sphingolipid-gated Ca2+ channel that we have previously described. These findings suggest that SCaMPER is a sphingolipid-gated Ca2+-permeable channel and support its role as a mediator of this pathway for intracellular Ca2+ signal transduction. |
| Databáze: | OpenAIRE |
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