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Structural and functional analyses were used to investigate the regulation of the inositol 1,4,5-trisphosphate (InsP3) receptor (InsP3R) by Ca2+. To define the structural determinants for Ca2+ binding, cDNAs encoding GST fusion proteins that covered the complete linear cytosolic sequence of the InsP3R-1 were expressed in bacteria. The fusion proteins were(More)
Striated muscle represents one of the best models for studies on Ca(2+) signalling. However, although much is known on the localisation and molecular interactions of the ryanodine receptors (RyRs), far less is known on the localisation and on the molecular interactions of the inositol trisphosphate receptors (InsP(3)Rs) in striated muscle cells. Recently,(More)
Binding of ATP to the inositol 1,4,5-trisphosphate receptor (IP(3)R) results in a more pronounced Ca(2+)release in the presence of inositol 1,4,5-trisphosphate (IP(3)). Two recently published studies demonstrated a different ATP sensitivity of IP(3)-induced Ca(2+)release in cell types expressing different IP(3)R isoforms. Cell types expressing mainly(More)
To study the Ca2+ regulation of the inositol 1,4,5-trisphosphate receptor (InsP3R) at the molecular level, we expressed various cytosolic and luminal regions of the mouse type I InsP3R as glutathione S-transferase fusion proteins. 45Ca2+ and ruthenium red overlay studies and Stains-all spectra and staining revealed both a cytosolic and a luminal Ca2+(More)
Inositol 1,4,5-trisphosphate (Ins(1,4,5)P3) induces Ca2+ oscillations and waves in Xenopus laevis oocytes. Microsomes from oocytes exhibit high-affinity binding for Ins(1,4,5)P3, and demonstrate Ins(1,4,5)P3-induced Ca2+ release. The Ins(1,4,5)P3 receptor (InsP3R) was purified from oocyte microsomes as a large tetrameric complex and shown to have a monomer(More)
The Ca2+ content of the intracellular Ca2+ stores controls the inositol 1,4,5-trisphosphate receptor (InsP3R) in the clonal cell line A7r5. This regulation was characterized with respect to the understanding of the "quantal" release phenomenon. Independent of the loading protocol used, increasing the Ca2+ content of the stores increased the sensitivity of(More)
In mammalian fertilization, inositol 1,4,5-trisphosphate receptor (IP3R)-dependent Ca2+ release is a crucial signaling event that originates from the vicinity of sperm-egg interaction and spreads as a wave throughout the egg cytoplasm. While it is known that Ca2+ is released by the type 1 IP3R in the egg cortex, the potential involvement of other isoform(More)
During maturation, mammalian oocytes undergo a series of changes that prepare them for fertilization. These events are regulated by kinases, most notably histone H1 and mitogen-activated protein kinase. Intracellular calcium ([Ca2+]i) oscillations participate in oocyte signaling, and it has been postulated that they play a role in oocyte maturation. In(More)
The inositol 1,4,5-trisphosphate (IP3) receptor (IP3R) is a universal intracellular Ca2+-release channel. It is activated after cell stimulation and plays a crucial role in the initiation and propagation of the complex spatio-temporal Ca2+ signals that control cellular processes as different as fertilization, cell division, cell migration, differentiation,(More)
  • Fabrizio de Mattia, Caroline Gubser, +9 authors Frank J M van Kuppeveld
  • 2009
Golgi antiapoptotic protein (GAAP) is a novel regulator of cell death that is highly conserved in eukaryotes and present in some poxviruses, but its molecular mechanism is unknown. Given that alterations in intracellular Ca(2+) homeostasis play an important role in determining cell sensitivity to apoptosis, we investigated if GAAP affected Ca(2+) signaling.(More)