An ordered pathway for the assembly of fungal ESCRT-containing ambient pH signalling complexes at the plasma membrane.
An ordered pathway for the assembly of fungal ESCRT-containing ambient pH signalling complexes at the plasma membrane.
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DOI：
10.1242/jcs.098897
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发表时间：
2012-04-01
影响因子：
4
通讯作者：
Peñalva MÁ
中科院分区：
文献类型：
--
作者：
Galindo A;Calcagno-Pizarelli AM;Arst HN Jr;Peñalva MÁ
真菌PAL/RIM信号通路除了涉及特定的蛋白质外，还涉及ESCRT复合体的几个组分，这表明pH信号蛋白聚集在内体平台上。在nidulans中，专有的Pal蛋白包括质膜受体PalH及其偶联的arrestin，在碱性pH条件下泛素化的PALF，以及三个潜在的内体ESCRT-III关联体，包括Vps32相互作用的Pala和PalC以及Vps24相互作用的calain样PalB。我们研究了通过将环境pH值改变为碱性来激活该途径后发生信号传递的亚细胞位置。Vps32相互作用因子Pala和PalC不是定位于内体，而是以PalH、Vps23和Vps32依赖但Vps27不依赖的方式瞬时共存于碱性pH诱导的皮质结构。当Vps4缺乏时，这些皮质结构更加稳定，表明它们的半衰期取决于ESCRT-III的分解。下拉研究表明，Vps23与PALF有很强的相互作用，但免疫共沉淀仅与提取物中泛素化的PALF形式有关。我们证明，在生理水平表达的VPs23-GFP也被招募到皮质结构中，在VPs27Δ细胞中非常明显，其中VPs23-GFP在内体上的显著信号被消除，以PALf和碱性pH依赖的方式。双通道荧光显微镜显示PalC先于Pala到达皮质复合体。由于PalC的募集是PalA独立的，PalA的募集是PalC依赖的，但PalB独立的，这些数据完整了PAL蛋白在该途径中的参与顺序，并有力地支持了一个模型，即pH信号发生在含有ESCRT的质膜相关的复合体中，而不是内小体相关的复合体中。
The fungal pal/RIM signalling pathway, which regulates gene expression in response to environmental pH involves, in addition to dedicated proteins, several components of ESCRT complexes, which suggested that pH signalling proteins assemble on endosomal platforms. In Aspergillus nidulans, dedicated Pal proteins include the plasma membrane receptor PalH and its coupled arrestin, PalF, which becomes ubiquitylated in alkaline pH conditions, and three potentially endosomal ESCRT-III associates, including Vps32 interactors PalA and PalC and Vps24 interactor calpain-like PalB. We studied the subcellular locations at which signalling takes place after activating the pathway by shifting ambient pH to alkalinity. Rather than localising to endosomes, Vps32 interactors PalA and PalC transiently colocalise at alkaline-pH-induced cortical structures in a PalH-, Vps23- and Vps32-dependent but Vps27-independent manner. These cortical structures are much more stable when Vps4 is deficient, indicating that their half-life depends on ESCRT-III disassembly. Pull-down studies revealed that Vps23 interacts strongly with PalF, but co-immunoprecipitates exclusively with ubiquitylated PalF forms from extracts. We demonstrate that Vps23–GFP, expressed at physiological levels, is also recruited to cortical structures, very conspicuous in vps27Δ cells in which the prominent signal of Vps23–GFP on endosomes is eliminated, in a PalF- and alkaline pH-dependent manner. Dual-channel epifluorescence microscopy showed that PalC arrives at cortical complexes before PalA. As PalC recruitment is PalA independent and PalA recruitment is PalC dependent but PalB independent, these data complete the participation order of Pal proteins in the pathway and strongly support a model in which pH signalling takes place in ESCRT-containing, plasma-membrane-associated, rather than endosome-associated, complexes.
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DOI：
10.1038/nrm2937
发表时间：
2010-08
期刊：
Nature reviews. Molecular cell biology
影响因子：
--
作者：
通讯作者：
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影响因子：
3
作者：
Hervas-Aguilar, America;Rodriguez-Galan, Olga;Galindo, Antonio;Abenza, Juan F.;Arst, Herbert N., Jr.;Penalva, Miguel A.
通讯作者：
Penalva, Miguel A.
影响因子：
3.3
作者：
Pantazopoulou, Areti;Penalva, Miguel A.
通讯作者：
Penalva, Miguel A.
影响因子：
11.4
作者：
Díez, E;Alvaro, J;Peñalva, MA
通讯作者：
Peñalva, MA
DOI：
10.1074/jbc.m808645200
发表时间：
2009-02-13
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Rodríguez-Galán O;Galindo A;Hervás-Aguilar A;Arst HN Jr;Peñalva MA
通讯作者：
Peñalva MA