InsP3-mediated intracellular calcium signalling is altered by expression of synaptojanin-1
| Autor: | Brenda DeGray, Eunkyung Lee, Pietro De Camilli, Per Uhlén, Markus R. Wenk, Barbara E. Ehrlich, Friedrich W. Johenning |
|---|---|
| Rok vydání: | 2004 |
| Předmět: |
Phosphatidylinositol 4
5-Diphosphate Phosphatase Intracellular Space Nerve Tissue Proteins CHO Cells Inositol 1 4 5-Trisphosphate Endocytosis Endoplasmic Reticulum Biochemistry Clathrin Calcium in biology Cell Line chemistry.chemical_compound Adenosine Triphosphate Phosphatidylinositol Phosphates Catalytic Domain Cricetinae Animals Inositol Phosphatidylinositol Calcium Signaling Molecular Biology Calcium signaling biology Inositol Polyphosphate 5-Phosphatases Membrane Proteins Cell Biology Phosphoric Monoester Hydrolases Cell biology chemistry biology.protein Calcium Intracellular Research Article |
| Zdroj: | The Biochemical journal. 382(Pt 2) |
| ISSN: | 1470-8728 |
| Popis: | Phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2] plays an important physiological role as a precursor for the InsP3-mediated intracellular calcium (Ca2+) signalling cascade. It also regulates membrane trafficking, actin function and transmembrane proteins. SJ-1 (synaptojanin-1), a phosphoinositide phosphatase, regulates the turnover of a PtdIns(4,5)P2 pool involved in clathrin and actin dynamics at the cell surface. We tested the interrelationship of this pool with PtdIns(4,5)P2 pools involved in Ca2+ signalling by expressing in Chinese-hamster ovary cells full-length SJ-1 or its 5-Pase (inositol 5-phosphatase) domain. SJ-1 significantly attenuated the generation of Ca2+ oscillations induced by ATP and the 5-Pase domain mimicked this effect. These changes correlated with increased PtdIns(4,5)P2 phosphatase activity of cellular extracts. Overexpression of the endoplasmic reticulum-anchored PtdIns(4)P phosphatase Sac1 did not affect Ca2+ oscillations, although it increased the Ca2+ efflux rate from intracellular stores. The ability of SJ-1 to alter intracellular Ca2+ signalling indicates a close functional interrelationship between plasma membrane PtdIns(4,5)P2 pools that control actin and endocytosis and those involved in the regulation of specific spatio-temporal Ca2+ signals. |
| Databáze: | OpenAIRE |
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