Participation of proteasome-associating complex PC500 in starfish oocyte maturation as revealed by monoclonal antibodies.
We previously reported that immature starfish oocytes contain a novel 530-kDa proteasome-associating complex PC500 [previously named PC530; E. Tanaka, M. Takagi Sawada, C. Morinaga, H. Yokosawa, H. Sawada, Isolation and characterization of a novel 530-kDa protein complex (PC 530) capable of associating with the 20S proteasome from star fish oocytes, Arch. Biochem. Biophys. 374 (2000) 181-188]. In the present study, in order to obtain an insight into the biological function of this complex, we investigated the effects of anti-PC500 monoclonal antibodies on oocyte maturation of the starfish Asterina pectinifera. A monoclonal antibody 7C5 strongly inhibited germinal vesicle breakdown (GVBD) in a concentration-dependent manner. In contrast to the inhibitory effect of the 7C5 antibody on GVBD, no inhibition of egg cleavage was observed in a 7C5-antibody-microinjected single blastomere in a 2-cell stage embryo. These results indicate that PC500 plays a key role in starfish oocyte maturation in a meiosis-specific manner.
Sawada
Michiko Takagi
MT
Research Institute of Genome-based Biofactory, National Institute of Advanced Industrial Science and Technology (AIST), Toyohira-ku, Sapporo 062-8517, Japan. takagi.sawadamichiko@aist.go.jp
Tamura
Tomohiro
T
Mitani
Yasuo
Y
Kaya
Motohiro
M
Ito
Genzo
G
Hashimoto
Hiroshi
H
Sawada
Hitoshi
H
D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry*; D015180:Electrophoresis, Gel, Two-Dimensional; D051379:Mice; D008807:Mice, Inbred BALB C; D008928:Mitochondria / Q000378:metabolism; D046912:Multiprotein Complexes / Q000737:chemistry; D009865:Oocytes / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex / Q000737:chemistry / Q000378:metabolism*; D013215:Starfish; D025801:Ubiquitin / Q000737:chemistry
D000911:Antibodies, Monoclonal; D046912:Multiprotein Complexes; D025801:Ubiquitin; D046988:Proteasome Endopeptidase Complex; C061553:ATP dependent 26S protease