Dissecting the function of the different chitin synthases in vegetative growth and sexual development in Neurospora crassa
Dissecting the function of the different chitin synthases in vegetative growth and sexual development in Neurospora crassa
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DOI：
10.1016/j.fgb.2015.01.002
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发表时间：
2015-02-01
影响因子：
3
通讯作者：
Riquelme, Meritxell
中科院分区：
文献类型：
--
作者：
Fajardo-Someraa'l, Rosa A.;Joehnk, Bastian;Riquelme, Meritxell
几丁质是真菌细胞壁中最重要的碳水化合物之一，由几丁质酶（CHS）合成。在粗糙脉孢菌基因组中已鉴定出7个编码CHS的序列。此前，CHS-1、CHS-3和CHS-6在Spitzenkorper（Spk）岩心和正在发育的隔片中被发现。我们研究了每个CHS在N.粗鲁。比较了荧光蛋白标记的各CHS的细胞分布以及相应基因缺失对营养生长和性发育的影响。CHS-2、CHS-4、CHS-5和CHS-7也存在于Spk的核心和营养菌丝的隔膜形成中。随着隔环的发育，CHS-2-GFP一直停留在隔环的生长边缘，直到隔孔周围。此外，所有CHS都位于分生孢子梗的横壁上。CHS-1-m和CHS-5-GFP或CHS-2-GFP在Spk和隔中发生部分共定位。缺失突变体的分析表明，CHS-6主要在菌丝延伸和子囊孢子形成中起作用。CHS-5在气生菌丝、分生孢子和子囊孢子的形成中起作用，CHS-3在子囊盘发育中起作用，CHS-7在上述所有方面起作用。我们发现，chs-7/csmB实现了有性功能，chs-6/chsG实现了营养生长功能。chs-2/chsA在A. crassa中具有有性功能，而在构巢曲霉中没有，反之亦然。nidulans，而N.粗鲁。这表明不同种类的CHS可以在各种真菌中实现不同的发育功能。CHS-1-GFP、CHS-4-GFP和CHS-5-GFP的免疫沉淀和质谱鉴定了每个CHS的不同推定相互作用蛋白。总的来说，我们的研究结果表明，有不同的群体的壳聚糖体，每个携带特定的CHSs，在不同的发展阶段具有特定的作用。(C)2015 Elsevier Inc. All rights reserved.
Chitin, one of the most important carbohydrates of the fungal cell wall, is synthesized by chitin synthases (CHS). Seven sequences encoding CHSs have been identified in the genome of Neurospora crassa. Previously, CHS-1, -3 and -6 were found at the Spitzenkorper (Spk) core and developing septa. We investigated the functional importance of each CHS in growth and development of N. crassa. The cellular distribution of each CHS tagged with fluorescent proteins and the impact of corresponding gene deletions on vegetative growth and sexual development were compared. CHS-2, -4, -5 and -7 were also found at the core of the Spk and in forming septa in vegetative hyphae. As the septum ring developed, CHS-2-GFP remained at the growing edge of the septum until it localized around the septal pore. In addition, all CHSs were located in cross-walls of conidiophores. A partial co-localization of CHS-1-m and CHS-5-GFP or CHS-2-GFP occurred in the Spk and septa. Analyses of deletion mutants suggested that CHS-6 has a role primarily in hyphal extension and ascospore formation. CHS-5 in aerial hyphae, conidia and ascospore formation, CHS-3 in perithecia development and CHS-7 in all of the aforementioned. We show that chs-7/csmB fulfills a sexual function and chs-6/chsG fulfills a vegetative growth function in N. crassa but not in Aspergillus nidulans, whereas vice versa chs-2/chsA fulfills a sexual function in A. nidulans but not in N. crassa. This suggests that different classes of CHSs can fulfill distinct developmental functions in various fungi. Immunoprecipitation followed by mass spectrometry of CHS-1-GFP, CHS-4-GFP and CHS-5-GFP identified distinct putative interacting proteins for each CHS. Collectively, our results suggest that there are distinct populations of chitosomes, each carrying specific CHSs, with particular roles during different developmental stages. (C) 2015 Elsevier Inc. All rights reserved.