The Cell End Marker Protein TeaC Is Involved in Growth Directionality and Septation in Aspergillus nidulans
The Cell End Marker Protein TeaC Is Involved in Growth Directionality and Septation in Aspergillus nidulans
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DOI：
10.1128/ec.00251-08
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发表时间：
2009-07-01
期刊：
影响因子：
--
通讯作者：
Fischer, Reinhard
中科院分区：
文献类型：
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作者：
Higashitsuji, Yuhei;Herrero, Saturnino;Fischer, Reinhard
丝状真菌的极化生长依赖于微管（MT）和肌动蛋白细胞骨架的正确空间组织。在粟酒裂殖酵母中，已经表明MT细胞骨架是传递所谓的细胞末端标记蛋白质所必需的。例如，在一个实施例中，Tea 1和Tea 4，到细胞两极。随后，这些标记物募集极化生长所需的几种蛋白质，例如。例如，在一个实施例中，一种催化肌动蛋白索形成的酶。最新的结果表明，这种机制是保守的裂变酵母构巢曲霉。在这里，我们的特点是TeaC，一个假定的同源物Tea 4。TeaC和Tea 4之间的序列同一性仅为12.5%，但它们都在N-末端区域共享SH 3结构域。teaC的缺失影响菌丝的极性生长和方向性。而野生型菌丝生长直线，菌丝的突变体生长在一个Z字形的方式，类似于teaA缺失（tea 1）菌株的菌丝。观察到一些小的无核隔室。teaC的过表达抑制了分生孢子的分裂，并引起萌发分生孢子的异常肿胀。在协议中的两个角色，在两极化的增长和分隔，TeaC本地化的菌丝尖端和隔膜。TeaC在菌丝尖端与细胞末端标记蛋白TeaA相互作用，在菌丝尖端和隔膜与形成SepA相互作用。
Polarized growth in filamentous fungi depends on the correct spatial organization of the microtubule (MT) and actin cytoskeleton. In Schizosaccharomyces pombe it was shown that the MT cytoskeleton is required for the delivery of so-called cell end marker proteins, e. g., Tea1 and Tea4, to the cell poles. Subsequently, these markers recruit several proteins required for polarized growth, e. g., a formin, which catalyzes actin cable formation. The latest results suggest that this machinery is conserved from fission yeast to Aspergillus nidulans. Here, we have characterized TeaC, a putative homologue of Tea4. Sequence identity between TeaC and Tea4 is only 12.5%, but they both share an SH3 domain in the N-terminal region. Deletion of teaC affected polarized growth and hyphal directionality. Whereas wild-type hyphae grow straight, hyphae of the mutant grow in a zig-zag way, similar to the hyphae of teaA deletion (tea1) strains. Some small, anucleate compartments were observed. Overexpression of teaC repressed septation and caused abnormal swelling of germinating conidia. In agreement with the two roles in polarized growth and in septation, TeaC localized to hyphal tips and to septa. TeaC interacted with the cell end marker protein TeaA at hyphal tips and with the formin SepA at hyphal tips and at septa.