Involvement of Rabphilin-3A in cortical granule exocytosis in mouse eggs. J Cell Biol 1996 Dec;135(6 Pt 2):1741-7
Date
12/01/1996Pubmed ID
8991087Pubmed Central ID
PMC2133937DOI
10.1083/jcb.135.6.1741Scopus ID
2-s2.0-0030461545 (requires institutional sign-in at Scopus site) 43 CitationsAbstract
Rabphilin-3A is a putative target protein for Rab3A, a member of the small GTP-binding protein superfamily that has been suggested to play a role in regulated exocytosis in presynapses. In this study we determined the expression and the function of Rabphilin-3A in mouse eggs at fertilization. Rabphilin-3A mRNA and protein were detected by reverse transcriptase-PCR and immunoblot analysis, respectively, in metaphase II mouse eggs. Immunofluorescence analysis showed that Rabphilin-3A protein was distributed in the cortical region in eggs. Sperm induces cortical granule (CG) exocytosis via an increase in cytosolic Ca2+ at fertilization. We microinjected the NH2- or COOH-terminal fragment of recombinant Rabphilin-3A into metaphase II eggs. Neither treatments altered the sperm-induced cytosolic Ca2+ increase, but both inhibited CG exocytosis in a dose-dependent manner. The NH2-terminal fragment was more effective than the COOH-terminal fragment. Full-length Rabphilin-3A did not affect CG exocytosis, but it attenuated the inhibition of CG exocytosis by the NH2-terminal fragment. These results show that Rabphilin-3A is involved in Ca(2+)-dependent CG exocytosis at fertilization in mouse eggs.
Author List
Masumoto N, Sasaki T, Tahara M, Mammoto A, Ikebuchi Y, Tasaka K, Tokunaga M, Takai Y, Miyake AAuthor
Akiko Mammoto MD, PhD Associate Professor in the Pediatrics department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
Adaptor Proteins, Signal TransducingAnimals
Calcium
Cytoplasmic Granules
Exocytosis
Female
Fertilization
GTP-Binding Proteins
Gene Expression
Glutathione Transferase
Hemagglutinins
Male
Metaphase
Mice
Mice, Inbred Strains
Molecular Sequence Data
Nerve Tissue Proteins
Ovum
Peptide Fragments
RNA, Messenger
Signal Transduction
Vesicular Transport Proteins
rab GTP-Binding Proteins
