Department of Microbiology and Molecular Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon, 34134, Republic of Korea.
Y-Biologics Co. Ltd., Daejeon, 34013, Republic of Korea.
J Microbiol. 2024 Jan;62(1):21-31. doi: 10.1007/s12275-023-00097-7. Epub 2024 Jan 5.
It was reported that LAMMER kinase in Schizosaccharomyces pombe plays an important role in cation-dependent and galactose-specific flocculation. Analogous to other flocculating yeasts, when cell wall extracts of the Δlkh1 strain were treated to the wild-type strain, it displayed flocculation. Gas2, a 1,3-β-glucanosyl transferase, was isolated from the EDTA-extracted cell-surface proteins in the Δlkh1 strain. While disruption of the gas2 gene was not lethal and reduced the flocculation activity of the ∆lkh1 strain, the expression of a secreted form of Gas2, in which the GPI anchor addition sequences had been removed, conferred the ability to flocculate upon the WT strain. The Gas2-mediated flocculation was strongly inhibited by galactose but not by glucose. Immunostaining analysis showed that the cell surface localization of Gas2 was crucial for the flocculation of fission yeast. In addition, we identified the regulation of mbx2 expression by Lkh1 using RT-qPCR. Taken together, we found that Lkh1 induces asexual flocculation by regulating not only the localization of Gas2 but also the transcription of gas2 through Mbx2.
据报道，裂殖酵母中的 LAMMER 激酶在依赖阳离子和半乳糖特异性絮凝中发挥重要作用。与其他絮凝酵母类似，当用 Δlkh1 菌株的细胞壁提取物处理野生型菌株时，它显示出絮凝性。Gas2 是一种 1,3-β-葡聚糖转移酶，从 Δlkh1 菌株的 EDTA 提取的细胞表面蛋白中分离出来。虽然 gas2 基因的破坏不是致死性的，并降低了 ∆lkh1 菌株的絮凝活性，但分泌形式的 Gas2 的表达，其中已经去除了 GPI 锚添加序列，赋予了 WT 菌株絮凝能力。Gas2 介导的絮凝被半乳糖强烈抑制，但不受葡萄糖抑制。免疫染色分析表明，Gas2 的细胞表面定位对于裂殖酵母的絮凝至关重要。此外，我们使用 RT-qPCR 鉴定了 Lkh1 对 mbx2 表达的调控。综上所述，我们发现 Lkh1 通过调节 Gas2 的定位以及通过 Mbx2 调节 gas2 的转录来诱导无性絮凝。
