PtaB, a lim-domain binding protein in Aspergillus fumigatus regulates biofilm formation and conidiation through distinct pathways
PtaB, a lim-domain binding protein in Aspergillus fumigatus regulates biofilm formation and conidiation through distinct pathways
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PtaB 是烟曲霉中的 lim 结构域结合蛋白，通过不同途径调节生物膜形成和分生孢子形成
DOI：
10.1111/cmi.12799
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发表时间：
2018
影响因子：
3.4
通讯作者：
Sheppard Donald C.
中科院分区：
文献类型：
--
作者：
Zhang Shizhu;Chen Yuan;Ma Zhihua;Chen Qiuyi;Ostapska Hanna;Gravelat Fabrice N.;Lu Ling;Sheppard Donald C.
烟曲霉胞外多糖半乳糖胺半乳聚糖（GAG）在介导粘附、生物膜形成和致病性等方面起着重要作用。发育调节剂梅达、StuA和索马调节GAG生物合成，但对这种调节的机制知之甚少。PtaB是一种lim-domain结合蛋白，与转录因子索马相互作用，是正常分生孢子和生物膜形成所必需的。破坏ptaB导致受损的GAG生产和分生孢子与GAG生物合成基因（uge 3和agd 3），发育调节因子（medAandstuA）的表达显着减少，并参与核心分生孢子途径的基因。在Δ ptaB突变体中，medA的过表达和fuge 3和agd 3的双重过表达增加了生物膜的形成，但没有分生孢子，而核心分生孢子形成基因的过表达拯救了分生孢子，但没有生物膜的形成。过表达的stuA适度增加分生孢子和生物膜的形成。对ptaB截短突变体的分析显示，lim-结构域结合区的过表达恢复了分生孢子的形成，但没有恢复生物膜的形成，这表明ptaB可能通过与不同的伴侣相互作用来控制这些过程。这些研究证实，PtaB在底物可用性和聚合物脱乙酰化水平上控制GAG生物合成，并且PtaB介导的生物膜形成和孢子化在很大程度上是独立的途径。
The exopolysaccharide galactosaminogalactan (GAG) plays an important role in mediating adhesion, biofilm formation, and virulence in the pathogenic fungusAspergillus fumigatus. The developmental modifiers MedA, StuA, and SomA regulate GAG biosynthesis, but the mechanisms underlying this regulation are poorly understood. PtaB is a lim‐domain binding protein that interacts with the transcription factor SomA and is required for normal conidiation and biofilm formation. Disruption ofptaBresulted in impaired GAG production and conidiation in association with a markedly reduced expression of GAG biosynthetic genes (uge3andagd3), developmental regulators (medAandstuA), and genes involved in the core conidiation pathway. Overexpression ofmedAand dual overexpression ofuge3andagd3in the ΔptaBmutant increased biofilm formation but not conidiation, whereas overexpression of core conidiation genes rescued conidiation but not biofilm formation. Overexpression ofstuAmodestly increased both conidiation and biofilm formation. Analysis ofptaBtruncation mutants revealed that overexpression of the lim‐domain binding region restored conidiation but not biofilm formation, suggesting thatptaBmay govern these processes by interacting with different partners. These studies establish that PtaB governs GAG biosynthesis at the level of substrate availability and polymer deacetylation and that PtaB‐mediated biofilm formation and conidiation are largely independent pathways.