In the budding yeast Saccharomyces cerevisiae, Svl3 and Pam1 proteins work as functional homologues. Loss of their function causes increased levels of chitin deposition in the cell wall and temperature sensitivity, suggesting their involvement in cell wall formation. We found that the N‐ and C‐termini of these proteins have distinctive and critical functions. They contain an N‐terminal part that has a probable 2‐dehydropantoate 2‐reductase domain. In Svl3, this part can be replaced with the yeast 2‐dehydropantoate 2‐reductase, Pan5, suggesting that Svl3 and its homologues may be able to mediate 2‐dehydropantoate 2‐reductase function. On the other hand, Svl3 is recruited to the bud tip and bud neck via multiple localization signals in the C‐terminal part. One of such signals is the lysine‐rich region located in the C‐terminal end. The function and localization of Svl3 are significantly disrupted by the loss of this lysine‐rich region; however, its localization is not completely abolished by the mutation because another localization signal enables appropriate transport. Svl3 and Pam1 orthologues are found in cells across fungal species. The Svl3 orthologues of Candida glabrata can complement the loss of Svl3 and Pam1 in S. cerevisiae. C. glabrata cells lacking the SVL3 and PAM1 orthologue genes exhibit phenotypes similar to those observed in svl3∆pam1∆ S. cerevisiae cells. Thus, Svl3 homologues may be generally required for the assembly of the cell wall in fungal cells.

中文翻译：

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Svl3和Pam1的功能特征是酵母细胞中适当的细胞壁形成所必需的。

在发芽酵母中酿酒酵母，Svl3和Pam1蛋白充当功能同源物。它们功能的丧失导致几丁质在细胞壁中的沉积水平增加和温度敏感性，表明它们参与了细胞壁的形成。我们发现这些蛋白质的N和C末端具有独特而关键的功能。它们包含一个N末端部分，该部分可能具有2-dehydropantoate 2-reasease域。在Svl3中，此部分可以用酵母2-脱氢泛酸2-还原酶代替，这表明Svl3及其同系物可能能够介导2-脱氢泛酸2-还原酶的功能。另一方面，Svl3通过C末端部分中的多个定位信号被募集到芽尖和芽颈。这种信号之一是位于C末端的富含赖氨酸的区域。Svl3的功能和定位因富含赖氨酸的区域的缺失而受到严重破坏。但是，由于另一种定位信号可以进行适当的转运，因此突变并未完全消除其定位。在真菌种类的细胞中发现了Svl3和Pam1直向同源物。的Svl3直系同源物光滑念珠菌可弥补酿酒酵母中Svl3和Pam1的丢失。缺少SVL3和PAM1直向同源基因的光滑小球藻细胞表现出与svl3Δpam1Δ酿酒酵母细胞相似的表型。因此，真菌细胞中细胞壁的组装通常可能需要Svl3同源物。