Sugimoto K, Nishida M, Otsuka M, Makino K, Ohkubo K, Mori Y, Morii T. Novel Real-Time Sensors to Quantitatively Assess In Vivo Inositol 1,4,5-Trisphosphate Production in Intact Cells.
ACTA ACUST UNITED AC 2004;
11:475-85. [PMID:
15123242 DOI:
10.1016/j.chembiol.2004.03.019]
[Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2003] [Revised: 01/02/2004] [Accepted: 01/09/2004] [Indexed: 11/16/2022]
Abstract
Real-time observation of messenger molecules in individual intact cells is essential for physiological studies of signaling mechanisms. We have developed a novel inositol 1,4,5-trisphosphate (IP(3)) sensor based on the pleckstrin homology (PH) domain from phospholipase C (PLC) delta. The environmentally sensitive fluorophore 6-bromoacetyl-2-dimethyl-aminonaphtalene was conjugated to the genetically introduced cysteine at the mouth of the IP(3) binding pocket for enhanced IP(3) selectivity and for rapid and direct visualization of intracellular IP(3) > or = 0.5 microM as fluorescence emission decreased. The probe, tagged with arginine-rich sequences for efficient translocation into various cell types, revealed a major contribution of Ca2+ influx to PLC-mediated IP(3) production that boosts Ca2+ release from endoplasmic reticulum. Thus, our IP(3) probe was extremely effective to quantitatively assess real-time physiological IP(3) production via those pathways formed only in the intact cellular configuration.
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