Organization and Dynamics of the Aspergillus nidulans Golgi during Apical Extension and Mitosis
Organization and Dynamics of the Aspergillus nidulans Golgi during Apical Extension and Mitosis
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DOI：
10.1091/mbc.e09-03-0254
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发表时间：
2009-10-15
影响因子：
3.3
通讯作者：
Penalva, Miguel A.
中科院分区：
文献类型：
--
作者：
Pantazopoulou, Areti;Penalva, Miguel A.
构巢曲霉菌丝仅通过顶端延伸生长。标记有mRFP标记的PHOSBP结构域的高尔基体等价物（GE）形成了一个显着极化，动态网络的环形和有孔池，保持完整的“封闭”有丝分裂。mRFP-PHOSBP GE与生长顶点相关，在生长顶点处分泌占主导地位，但不会向尖端进行长距离移动，这可能是其极化的原因。mRFP-PHOSBP GE与trans-Golgi常驻Sec 7重叠，但不与早期Golgi标记物GrhA（Grh 1）-GFP的极化增生共定位，表明早期和晚期Golgi膜在空间上分离。AnSec 23-GFP ER出口位点（ERES）是许多相对静止的灶，定位于整个细胞。然而，它们的密度是最大的尖端附近，相关的优势，早期和trans-Golgi元素在这一地区。而GrhA-GFP结构和ERES到达顶端圆顶，mRFP-PHOSBP GE被排除在该区域之外，该区域包含内体动力蛋白加载区。在latrunculin介导的F-肌动蛋白破坏后，mRFP-PHOSBP GEs片段化，并且像AnSec 23-GFP ERES一样去磷酸化。布雷菲德菌素A短暂地将晚期和早期GE分别折叠成含有Sec 7/mRFP-PHOSBP和GrhA-GFP的不同聚集体，暂时阻止顶端延伸。快速增长后重新启动冲洗，与重新获得正常的高尔基体组织，我们的结论是，需要顶端的延伸。
Aspergillus nidulans hyphae grow exclusively by apical extension. Golgi equivalents (GEs) labeled with mRFP-tagged PHOSBP domain form a markedly polarized, dynamic network of ring-shaped and fenestrated cisternae that remains intact during "closed" mitosis. mRFP-PHOSBP GEs advance associated with the growing apex where secretion predominates but do not undergo long-distance movement toward the tip that could account for their polarization. mRFP-PHOSBP GEs overlap with the trans-Golgi resident Sec7 but do not colocalize with also polarized accretions of the early Golgi marker GrhA(Grh1)-GFP, indicating that early and late Golgi membranes segregate spatially. AnSec23-GFP ER exit sites (ERES) are numerous, relatively static foci localizing across the entire cell. However, their density is greatest near the tip, correlating with predominance of early and trans-Golgi elements in this region. Whereas GrhA-GFP structures and ERES reach the apical dome, mRFP-PHOSBP GEs are excluded from this region, which contains the endosome dynein loading zone. After latrunculin-mediated F-actin disruption, mRFP-PHOSBP GEs fragment and, like AnSec23-GFP ERES, depolarize. Brefeldin A transiently collapses late and early GEs into distinct aggregates containing Sec7/mRFP-PHOSBP and GrhA-GFP, respectively, temporarily arresting apical extension. Rapid growth reinitiates after washout, correlating with reacquisition of the normal Golgi organization that, we conclude, is required for apical extension.