Non-SCF-type F-box protein Roy1/Ymr258c interacts with a Rab5-like GTPase Ypt52 and inhibits Ypt52 function.
Non-SCF-type F-box protein Roy1/Ymr258c interacts with a Rab5-like GTPase Ypt52 and inhibits Ypt52 function.
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DOI：
10.1091/mbc.e10-08-0716
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发表时间：
2011-05
影响因子：
3.3
通讯作者：
Kamura T
中科院分区：
文献类型：
--
作者：
Liu Y;Nakatsukasa K;Kotera M;Kanada A;Nishimura T;Kishi T;Mimura S;Kamura T
非SCF型F-box蛋白Roy 1与Rab 5样小GT3 Ypt 52相互作用。Skp 1是Roy 1和Ypt 52相互作用不可或缺的。Roy 1与GDP和无核苷酸形式的Ypt 52结合，并抑制GTP结合的活性Ypt 52的形成。Roy 1通过抑制Ypt 52负性调节细胞活力和细胞内转运。Skp 1/Cul 1/F-box（SCF）-型F-box蛋白是Cullin-RING SCF泛素E3连接酶的组分，其参与许多细胞过程。然而，非SCF型F-box蛋白的功能在很大程度上仍然未知。Rab 5样小鸟苷5′-三磷酸酶Vps 21/Ypt 51是细胞内转运的关键调节因子;然而，其亚型Ypt 52和Ypt 53的缺失仅导致细胞内转运的适度抑制。因此，这些蛋白质的功能在很大程度上仍然难以捉摸。在这里，我们分析了以前未表征的非SCF型F盒蛋白，Roy 1/Ymr 258 c，在酿酒酵母细胞生长和细胞内运输的作用。Roy 1在生理条件下与Ypt 52结合，Skp 1是Roy 1与Ypt 52结合所必需的。vps 21 Δ酵母细胞在细胞生长和细胞内运输方面表现出严重的缺陷，而roy 1的同时缺失弥补了vps 21缺失引起的缺陷。然而，roy 1 Δ vps 21 Δ细胞中ypt 52的额外破坏在很大程度上抑制了在roy 1 Δ vps 21 Δ细胞中观察到的细胞生长和运输。我们证明Roy 1与鸟苷5′-二磷酸结合和无核苷酸的Ypt 52相互作用，从而抑制鸟苷5′-三磷酸结合的活性Ypt 52的形成。因此，这些结果表明Roy 1通过抑制Ypt 52来负调节细胞活力和细胞内转运。
Non–SCF-type F-box protein Roy1 interacts with the Rab5-like small GTPase Ypt52. Skp1 is indispensable for the interaction of Roy1 and Ypt52. Roy1 binds to GDP and the nucleotide-free form of Ypt52 and inhibits the formation of GTP-bound, active Ypt52. Roy1 negatively modulates cell viability and intracellular transport by suppressing Ypt52. Skp1/Cul1/F-box (SCF)–type F-box proteins are a component of the Cullin-RING SCF ubiquitin E3 ligase, which is involved in numerous cellular processes. However, the function of non–SCF-type F-box proteins remains largely unknown. The Rab5-like small guanosine 5′-triphosphatase Vps21/Ypt51 is a key regulator of intracellular transportation; however, deletion of its isoforms, Ypt52 and Ypt53, results in only a modest inhibition of intracellular trafficking. The function of these proteins therefore remains largely elusive. Here we analyze the role of a previously uncharacterized non–SCF-type F-box protein, Roy1/Ymr258c, in cell growth and intracellular transport in Saccharomyces cerevisiae. Roy1 binds to Ypt52 under physiological conditions, and Skp1 is indispensable for the association of Roy1 with Ypt52. The vps21Δ yeast cells exhibit severe deficiencies in cell growth and intracellular trafficking, whereas simultaneous deletion of roy1 alleviates the defects caused by deletion of vps21. However, additional disruption of ypt52 in roy1Δvps21Δ cells largely suppresses the cell growth and trafficking observed in roy1Δvps21Δ cells. We demonstrate that Roy1 interacts with guanosine 5′-diphosphate–bound and nucleotide-free Ypt52 and thereby inhibits the formation of guanosine 5′-triphosphate–bound, active Ypt52. These results thus indicate that Roy1 negatively modulates cell viability and intracellular transport by suppressing Ypt52.