van Leeuwe Tim M, Wattjes Jasper, Niehues Anna, Forn-Cuní Gabriel, Geoffrion Nicholas, Mélida Hugo, Arentshorst Mark, Molina Antonio, Tsang Adrian, Meijer Annemarie H, Moerschbacher Bruno M, Punt Peter J, Ram Arthur F J
Leiden University, Institute of Biology Leiden, Molecular Microbiology and Biotechnology, Sylviusweg 72, 2333 BE Leiden, the Netherlands.
Institute for Biology and Biotechnology of Plants, University of Muenster, Schlossplatz 8, 48143 Münster, Germany.
Cell Surf. 2020 Mar 21;6:100039. doi: 10.1016/j.tcsw.2020.100039. eCollection 2020 Dec.
Chitin is an important fungal cell wall component that is cross-linked to β-glucan for structural integrity. Acquisition of chitin to glucan cross-links has previously been shown to be performed by transglycosylation enzymes in , called Congo Red hypersensitive (Crh) enzymes. Here, we characterized the impact of deleting all seven members of the gene family () in on cell wall integrity, cell wall composition and genome-wide gene expression. In this study, we show that the seven-fold knockout strain shows slightly compact growth on plates, but no increased sensitivity to cell wall perturbing compounds. Additionally, we found that the cell wall composition of this knockout strain was virtually identical to that of the wild type. In congruence with these data, genome-wide expression analysis revealed very limited changes in gene expression and no signs of activation of the cell wall integrity response pathway. However, deleting the entire gene family in cell wall mutants that are deficient in either galactofuranose or α-glucan, mainly α-1,3-glucan, resulted in a synthetic growth defect and an increased sensitivity towards Congo Red compared to the parental strains, respectively. Altogether, these results indicate that loss of the gene family in does not trigger the cell wall integrity response, but does play an important role in ensuring cell wall integrity in mutant strains with reduced galactofuranose or α-glucan.
几丁质是一种重要的真菌细胞壁成分，它与β-葡聚糖交联以维持结构完整性。先前已表明，几丁质与葡聚糖的交联是由酵母中的转糖基化酶完成的，这些酶被称为刚果红超敏（Crh）酶。在这里，我们研究了在酵母中删除Crh基因家族的所有七个成员对细胞壁完整性、细胞壁组成和全基因组基因表达的影响。在本研究中，我们发现七倍Crh基因敲除菌株在平板上生长略显紧凑，但对细胞壁干扰化合物的敏感性并未增加。此外，我们发现该敲除菌株的细胞壁组成与野生型几乎相同。与这些数据一致，全基因组表达分析显示基因表达变化非常有限，且没有细胞壁完整性反应途径激活的迹象。然而，在缺乏半乳呋喃糖或α-葡聚糖（主要是α-1,3-葡聚糖）的细胞壁突变体中删除整个Crh基因家族，分别导致了合成生长缺陷以及与亲本菌株相比对刚果红的敏感性增加。总之，这些结果表明，酵母中Crh基因家族的缺失不会触发细胞壁完整性反应，但在确保半乳呋喃糖或α-葡聚糖减少的突变菌株的细胞壁完整性方面确实发挥着重要作用。
