Jpn. J. Pharmacol. 74 (2), 125-137 (1997)
Structure and Function of Inositol 1,4,5-Trisphosphate Receptor
Yutaka Yoshida and Shoichi Imai (*)
Department of Pharmacology, Niigata University School of Medicine, Niigata
(*) To whom correspondence should be addressed.
Abstract: Generation of intracellular Ca2+ signals in response
to Ca2+-mobilizing stimuli is a critical event in the control of many cellular
processes. Inositol 1,4,5-trisphosphate (IP3) represents a dominant second
messenger subserving the release of Ca2+ from intracellular store sites.
The protein on the surface of which the IP3 receptor is located comprises
an IP3-gated Ca2+ channel, and binding of IP3 to this receptor triggers
the release of Ca2+ through this channel. The receptor for IP3 displays
a close resemblance to the ryanodine receptor, another intracellular Ca2+
channel, in many molecular and physiological properties. Many lines of evidence
strongly suggest the central role that the IP3 receptor plays in the conversion
of numerous external stimuli to intracellular Ca2+ signals characterized
by complex spatiotemporal patterns such as Ca2+ waves and oscillations.
In this review, we shall summarize our current knowledge of the structure
and function of the IP3 receptor in order to understand the way how the
activity of this important receptor is regulated to accomodate itself to
the generation of diverse intracellular Ca2+ signals.
Keywords: Inositol 1,4,5-trisphosphate (IP3), IP3 receptor, Ryanodine
receptor, Ca2+-mobilization, Phospholipase C
Copyrightę The Japanese Pharmacological Society 1997
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