Molecular Characterization of the Starfish Inositol 1,4,5-Trisphosphate Receptor and Its Role during Oocyte Maturation and Fertilization

The release of calcium ions (Ca2+) from their intracellular stores is essential for the fertilization of oocytes of various species. The calcium pools can be induced to release Ca2+ via two main types of calcium channel receptor: the inositol 1,4,5-trisphosphate receptor (IP3R) and the ryanodine rec...

Full description

Saved in:
Bibliographic Details
Published in:The Journal of biological chemistry 2002-01, Vol.277 (4), p.2763-2772
Main Authors: Iwasaki, Hirohide, Chiba, Kazuyoshi, Uchiyama, Tsuyoshi, Yoshikawa, Fumio, Suzuki, Fumiko, Ikeda, Masako, Furuichi, Teiichi, Mikoshiba, Katsuhiko
Format: Article
Language:English
Subjects:
Amino Acid Sequence
Animals
Asteroidea
Calcium - metabolism
Calcium Channels - chemistry
Calcium Channels - genetics
Calcium Channels - metabolism
Cloning, Molecular
DNA, Complementary - metabolism
Dose-Response Relationship, Drug
Electrophoresis, Polyacrylamide Gel
Escherichia coli - metabolism
Fertilization
Glutathione Transferase - metabolism
Humans
Immunoblotting
Immunohistochemistry
inositol 1,4,5-trisphosphate receptor
Inositol 1,4,5-Trisphosphate Receptors
Ligands
Molecular Sequence Data
Oocytes - growth & development
Phylogeny
Protein Binding
Protein Structure, Tertiary
Receptors, Cytoplasmic and Nuclear - chemistry
Receptors, Cytoplasmic and Nuclear - genetics
Sequence Homology, Amino Acid
Starfish
Time Factors
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The release of calcium ions (Ca2+) from their intracellular stores is essential for the fertilization of oocytes of various species. The calcium pools can be induced to release Ca2+ via two main types of calcium channel receptor: the inositol 1,4,5-trisphosphate receptor (IP3R) and the ryanodine receptor. Starfish oocytes have often been used to study intracellular calcium mobilization during oocyte maturation and fertilization, but how the intracellular calcium channels contribute to intracellular calcium mobilization has never been understood fully, because these molecules have not been identified and no specific inhibitors of these channels have ever been found. In this study, we utilized a novel IP3R antagonist, the “IP3 sponge,” to investigate the role of IP3 during fertilization of the starfish oocyte. The IP3 sponge strongly and specifically competed with endogenous IP3R for binding to IP3. By injecting IP3 sponge into starfish oocyte, the increase in intracellular calcium and formation of the fertilization envelope were both dramatically blocked, although oocyte maturation was not blocked. To investigate the role of IP3R in the starfish oocyte more precisely, we cloned IP3R from the ovary of starfish, and the predicted amino acid sequence indicated that the starfish IP3R has 58–68% identity to mammalian IP3R types 1, 2, and 3. We then raised antibodies that recognize starfish IP3R, and use of the antibodies to perform immunoblot analysis revealed that the level of expression of IP3R remained unchanged throughout oocyte maturation. An immunocytochemical study, however, revealed that the distribution of starfish IP3R changes during oocyte maturation.
ISSN:0021-9258
1083-351X
DOI:10.1074/jbc.M108839200