HAM-2 and HAM-3 are central for the assembly of the Neurospora STRIPAK complex at the nuclear envelope and regulate nuclear accumulation of the MAP kinase MAK-1 in a MAK-2-dependent manner
HAM-2 and HAM-3 are central for the assembly of the Neurospora STRIPAK complex at the nuclear envelope and regulate nuclear accumulation of the MAP kinase MAK-1 in a MAK-2-dependent manner
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DOI：
10.1111/mmi.12399
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发表时间：
2013-11-01
影响因子：
3.6
通讯作者：
Seiler, Stephan
中科院分区：
文献类型：
--
作者：
Dettmann, Anne;Heilig, Yvonne;Seiler, Stephan
细胞间通讯和体细胞融合对于真菌菌落建立、多细胞分化很重要，并且与宿主定植和致病物种的毒力有关。通过结合遗传、生化和活细胞成像技术，我们表征了粗糙脉孢菌STRIPAK复合物，该复合物对于自我信号传导至关重要，由六种蛋白质HAM-2/STRIP、HAM-3/striatin、HAM-4/SLMAP、MOB-3/phocein、PPG-1/PP2A-C和PP2A-A组成。我们描述了核心 STRIPAK 成分 HAM-2 和 HAM-3 是核膜复合物组装的中心，而磷酸酶 PPG-1 仅短暂地与该中心子复合物结合。我们的数据将 STRIPAK 复合物与两条 MAP 激酶途径联系起来：(i) 细胞壁完整性 MAP 激酶 MAK-1 的核积累取决于核膜上 STRIPAK 复合物的功能完整性，(ii) MAP 激酶 MAK-2 对 MOB-3 的磷酸化影响 MAK-1 的核积累。总之，这些数据支持一个模型，其中 MOB-3 的 MAK-2 依赖性磷酸化是 MAK-1 导入机制的一部分。尽管在没有核 MAK-1 积累的情况下自我通讯保持完整，支持协调强大的细胞间通讯的多种机制的存在，但适当的子实体形态依赖于 MOB-3 的 MAK-2 磷酸化 N 末端。
Intercellular communication and somatic cell fusion are important for fungal colony establishment, multicellular differentiation and have been associated with host colonization and virulence of pathogenic species. By a combination of genetic, biochemical and live cell imaging techniques, we characterized the Neurospora crassaSTRIPAK complex that is essential for self-signalling and consists of the six proteins HAM-2/STRIP, HAM-3/striatin, HAM-4/SLMAP, MOB-3/phocein, PPG-1/PP2A-C and PP2A-A. We describe that the core STRIPAK components HAM-2 and HAM-3 are central for the assembly of the complex at the nuclear envelope, while the phosphatase PPG-1 only transiently associates with this central subcomplex. Our data connect the STRIPAK complex with two MAP kinase pathways: (i) nuclear accumulation of the cell wall integrity MAP kinase MAK-1 depends on the functional integrity of the STRIPAK complex at the nuclear envelope, and (ii) phosphorylation of MOB-3 by the MAP kinase MAK-2 impacts the nuclear accumulation of MAK-1. In summary, these data support a model, in which MAK-2-dependent phosphorylation of MOB-3 is part of a MAK-1 import mechanism. Although self-communication remained intact in the absence of nuclear MAK-1 accumulation, supporting the presence of multiple mechanisms that co-ordinate robust intercellular communication, proper fruiting body morphology was dependent on the MAK-2-phosphorylated N-terminus of MOB-3.