The axial channel of the proteasome core particle is gated by the Rpt2 ATPase and controls both substrate entry and product release
The axial channel of the proteasome core particle is gated by the Rpt2 ATPase and controls both substrate entry and product release
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DOI：
10.1016/s1097-2765(01)00274-x
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发表时间：
2001-06-01
期刊：
影响因子：
16
通讯作者：
Finley, D
中科院分区：
文献类型：
--
作者：
Köhler, A;Cascio, P;Finley, D
底物通过通道进入蛋白酶体核心颗粒（CP），该通道在与调节颗粒（RP）结合时打开。使用酵母突变体，我们表明，通道开放介导的ATP酶结构域的Rpt2，六个ATP酶在RP。为了测试降解产物是否通过该通道排出，我们分析了它们的尺寸分布。它们的中位长度从一个开放通道CP突变体是40%以上，从野生型。因此，通道开放可以提高肽的产量足够长以在抗原呈递中起作用。这些实验表明，RP通道的门控控制底物进入和产物释放，并且受到RP底部的ATP酶的特异性调节。
Substrates enter the proteasome core particle (CP) through a channel that opens upon association with the regulatory particle (RP). Using yeast mutants, we show that channel opening is mediated by the ATPase domain of Rpt2, one of six ATPases in the RP. To test whether degradation products exit through this channel, we analyzed their size distribution. Their median length from an open-channel CP mutant was 40% greater than that from the wild-type. Thus, channel opening may enhance the yield of peptides long enough to function in antigen presentation. These experiments demonstrate that gating of the RP channel controls both substrate entry and product release, and is specifically regulated by an ATPase in the base of the RP.