KGRI Lecture Series: (Oct.18, 2019)"IP3 receptor/Ca2+ channel: from its discovery to a new paradigm in health and disease"


Keio University Global Research Institute (KGRI) aims to promote international research and educational exchange and invites those working in the forefront of research and education in Japan and overseas to give lectures.

On this occasion, Prof. Katsuhiko Mikoshiba from ShanghaiTech University will give a lecture titled "IP3 receptor/Ca2+ channel: from its discovery to a new paradigm in health and disease".

Date & time: Friday, Octber 18, 17:00-18:00 (Open 16:30)
Venue: Building 3 (North Wing) Lounge, Shinanomachi Campus, Keio University
Keio University Global Research Institute (KGRI)
Language: English
Open to anyone. No admission fee, Pre-registration not required.

Summary of Lecture:
Ca2+ plays an essential role in cell function. It conveys signals to the most important cell process but the detailed mechanism of signaling process is not clearly understood. We have discovered a key regulator of Ca2+ signaling, the IP3 receptor (IP3R) as a P400 protein greatly decreased in the cerebellum of Purkinje cell-degeneration mutant mice, and have subsequently cloned its cDNA.
We identified it is endoplasmic reticulum (ER) channel that convert GPCR-IP3 signals to Ca2+ signal at the ER to produce Ca2+ oscillation. We found that IP3R is essential for fertilization, dorso-ventral axis formation, neurite extension, cardiogenesis, exocrine secretion and behavior. We found IP3R interacts ER chaperons to protect from apoptosis caused by ER stress response. A newly discovered pseudo-IP3 which we named IRBIT that binds to IP3R and is involved in apoptosis regulation in association with anti-apoptotic proteins. We recently crystalized a large cytosolic domain (2217aa) of IP3R in the presence and absence of IP3 and solved the gating mechanism by biochemical and X-ray crystallographic analysis. We have identified a "leaflet" structure essential for allosteric channel gating, surrounded by functional molecules that may regulate IP3R activity to balance normal/abnormal state. I will discuss about a new paradigm in health and disease.

Professor Katsuhiko Mikoshiba:
Professor, SIAIS (Shanghai Institute for Advanced Immunochemical Studies), ShanghaiTech University
Specially Appointed Professor, Faculty of Science, Toho University
Guest Professor (Global) of Keio University


Department of Pharmacology School of Medicine
E-mail: keio_pharm[at]ml.keio.jp
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