Oog1, an oocyte-specific protein, interacts with Ras and Ras-signaling proteins during early embryogenesis.
We previously identified an oocyte-specific gene, Oogenesin 1 (Oog1), that encodes 326 amino acids containing a leucine zipper structure and a leucine-rich repeat. In the present study, to identify the interacting proteins of Oog1, we performed a yeast two-hybrid screening using a GV-oocyte cDNA library and found that Ral guanine nucleotide dissociation stimulator (RalGDS) is the binding partner of Oog1. Coimmunoprecipitation assay confirmed the interaction between Oog1 and RalGDS proteins. Colocalization experiments provide the evidence that the nuclear localization of RalGDS depends on the expression of Oog1. Interestingly, RalGDS protein localized in the nucleus rather than the cytoplasm between late 1-cell and early 2-cell stages, the time when Oog1 localizes in the nucleus. We also examined the interaction between Oog1 and Ras by GST pull-down assay and revealed that Oog1 interacts with Ras in a GTP-dependent manner. These findings suggest a role of Oog1 as a Ras-binding protein.
Laboratory of Reproductive Biology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan.
Satoshi
S
Tsukamoto
Ryo
R
Ihara
Akira
A
Aizawa
Shosei
S
Kishida
Akira
A
Kikuchi
Hiroshi
H
Imai
Naojiro
N
Minami
D000818:Animals; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D047108:Embryonic Development; D005260:Female; D015723:Gene Library; D006801:Humans; D051379:Mice; D009865:Oocytes / Q000378:metabolism*; D011485:Protein Binding; D012333:RNA, Messenger / Q000096:biosynthesis; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D020798:Two-Hybrid System Techniques; D020726:ral Guanine Nucleotide Exchange Factor / Q000096:biosynthesis / Q000378:metabolism*; D018631:ras Proteins / Q000378:metabolism*
D012333:RNA, Messenger; D014157:Transcription Factors; C487976:oogenesin protein, mouse; D020726:ral Guanine Nucleotide Exchange Factor; D018631:ras Proteins