Saccharomyces cerevisiae GTPase complex: Gtr1p–Gtr2p regulates cell-proliferation through Saccharomyces cerevisiae Ran-binding protein, Yrb2p
- 作者：Yonggang Wang ; Nobutaka Nakashima ; Takeshi Sekiguchi and Takeharu Nishimoto
- 关键词：Yrb2p ; RanBP3 ; Gtr1p ; Gtr2p ; Gsp1p ; RanGAP/Rna1p ; RanGEF/Prp20p ; Ran ; RagA/RRAG A ; RagC/RRAG C
- 刊名：Biochemical and Biophysical Research Communications
- 出版年：2005
- 期刊代码：159_0006291x
- 类别：bio
- 出版时间：2005
- 卷：336
- 期：2
- 页码：639-645
- 文件大小：232 K
摘要
A Gtr1p GTPase, the GDP mutant of which suppresses both temperature-sensitive mutants of Saccharomyces cerevisiae RanGEF/Prp20p and RanGAP/Rna1p, was presently found to interact with Yrb2p, the S. cerevisiae homologue of mammalian Ran-binding protein 3. Gtr1p bound the Ran-binding domain of Yrb2p. In contrast, Gtr2p, a partner of Gtr1p, did not bind Yrb2p, although it bound Gtr1p. A triple mutant: yrb2Δ gtr1Δ gtr2Δ was lethal, while a double mutant: gtr1Δ gtr2Δ survived well, indicating that Yrb2p protected cells from the killing effect of gtr1Δ gtr2Δ. Recombinant Gtr1p and Gtr2p were purified as a complex from Escherichia coli. The resulting Gtr1p–Gtr2p complex was comprised of an equal amount of Gtr1p and Gtr2p, which inhibited the Rna1p/Yrb2 dependent RanGAP activity. Thus, the Gtr1p–Gtr2p cycle was suggested to regulate the Ran cycle through Yrb2p.