The important role of actinin-like protein (AcnA) in cytokinesis and apical dominance of hyphal cells in Aspergillus nidulans.
The important role of actinin-like protein (AcnA) in cytokinesis and apical dominance of hyphal cells in Aspergillus nidulans.
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DOI：
10.1099/mic.0.029215-0
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发表时间：
2009-08
期刊：
影响因子：
1.5
通讯作者：
Jinjun Wang;Hongqing Hu;Sha Wang;Jie Shi;Shaochun Chen;Hua Wei;Xushi Xu;Ling Lu
中科院分区：
文献类型：
--
作者：
Jinjun Wang;Hongqing Hu;Sha Wang;Jie Shi;Shaochun Chen;Hua Wei;Xushi Xu;Ling Lu
肌动蛋白细胞骨架参与了真核细胞的许多过程，包括与多种肌动蛋白结合蛋白的相互作用，如肌动蛋白封端蛋白、肌动蛋白细丝核仁和肌动蛋白交联蛋白等。在这里，我们报告了丝状真菌Nidulans Aspergillusnidulans中的一种类放线蛋白(ACNA)的鉴定和特性。Alca(P)启动子抑制ACNA的缺失或ACNA的缺失不仅导致分离和分生孢子的明显异常，而且ACNA突变体还导致具有二叉分支的细胞失去顶端优势，新的顶端通过将现有顶端一分为二形成。因此，菌落的边缘呈扇形。此外，我们还发现GFP-ACNA融合的定位是相当动态的。在萌发孢子的各向同性扩展阶段，GFP-ACNA被组织成皮质斑块，细胞壁上有绳索包裹。随后，GFP-ACNA以组合双收缩环的形式定位于生长活跃的菌丝顶端和隔膜部位。我们的数据表明，ACNA在菌丝细胞的胞质分裂和顶端优势中发挥重要作用，可能是通过肌动蛋白依赖的极化维持和内环建立。据我们所知，这是关于丝状真菌中类肌动蛋白功能的第一份报告。
The actin cytoskeleton is involved in many processes in eukaryotic cells, including interaction with a wide variety of actin-binding proteins such as the actin-capping proteins, the actin filament nucleators and the actin cross-linking proteins. Here, we report the identification and characterization of an actinin-like protein (AcnA) from the filamentous fungus Aspergillus nidulans. Not only did the depletion of AcnA by alcA(p) promoter repression or the deletion of AcnA result in explicit abnormalities in septation and conidiation, but also the acnA mutants induced a loss of apical dominance in cells with dichotomous branching, in which a new branch was formed by splitting the existing tip in two. Consequently, the colony showed flabellate edges. Moreover, we found that the localization of the GFP-AcnA fusion was quite dynamic. In the isotropic expansion phase of the germinated spore, GFP-AcnA was organized as cortical patches with cables lining the cell wall. Subsequently, GFP-AcnA was localized to the actively growing hyphal tips and to the sites of septation in the form of combined double contractile rings. Our data suggest that AcnA plays an important role in cytokinesis and apical dominance of hyphal cells, possibly via actin-dependent polarization maintenance and medial ring establishment in A. nidulans. This is the first report, to our knowledge, of the function of an actinin-like protein in filamentous fungi.