Department of Molecular Microbiology, Washington University in St. Louis School of Medicine, St. Louis, MO 63110.
Proc Natl Acad Sci U S A. 2024 May 21;121(21):e2319707121. doi: 10.1073/pnas.2319707121. Epub 2024 May 14.
Glycogen is a glucose storage molecule composed of branched α-1,4-glucan chains, best known as an energy reserve that can be broken down to fuel central metabolism. Because fungal cells have a specialized need for glucose in building cell wall glucans, we investigated whether glycogen is used for this process. For these studies, we focused on the pathogenic yeast , which causes ~150,000 deaths per year worldwide. We identified two proteins that influence formation of both glycogen and the cell wall: glycogenin (Glg1), which initiates glycogen synthesis, and a protein that we call Glucan organizing enzyme 1 (Goe1). We found that cells missing Glg1 lack α-1,4-glucan in their walls, indicating that this material is derived from glycogen. Without Goe1, glycogen rosettes are mislocalized and β-1,3-glucan in the cell wall is reduced. Altogether, our results provide mechanisms for a close association between glycogen and cell wall.
糖原是一种由分支的α-1,4-葡聚糖链组成的葡萄糖储存分子,最常被认为是一种能量储备,可以分解为燃料中心代谢。由于真菌细胞在构建细胞壁葡聚糖时有特殊的葡萄糖需求,我们研究了糖原是否用于这个过程。在这些研究中,我们专注于致病性酵母,它每年在全球造成约 15 万人死亡。我们鉴定了两种影响糖原和细胞壁形成的蛋白质:糖原起始合成的糖原素(Glg1)和我们称之为葡聚糖组织酶 1(Goe1)的蛋白质。我们发现缺乏 Glg1 的细胞其细胞壁中缺乏α-1,4-葡聚糖,表明这种物质来源于糖原。没有 Goe1,糖原玫瑰花结定位错误,细胞壁中的β-1,3-葡聚糖减少。总的来说,我们的结果提供了糖原和细胞壁之间密切关联的机制。