The Arf-GTPase-activating protein Gcs1p is essential for sporulation and regulates the phospholipase D Spo14p.
The Arf-GTPase-activating protein Gcs1p is essential for sporulation and regulates the phospholipase D Spo14p.
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Arf-GTP 酶激活蛋白 Gcs1p 对于孢子形成至关重要，并调节磷脂酶 D Spo14p。
DOI：
10.1128/ec.5.1.112-124.2006
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
Engebrecht,Joanne
中科院分区：
文献类型：
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作者：
Connolly,JaimeE;Engebrecht,Joanne
SPO 14编码主要的酵母磷脂酶D（PLD），是孢子形成所必需的，并且介导新膜的合成，所述新膜包含通过减数分裂产生的单倍体核。PLD催化磷脂酰胆碱水解为磷脂酸（PA）和胆碱。PA刺激Arf-GTP酶激活蛋白（Arf-GAP），其参与膜运输事件和肌动蛋白细胞骨架功能。为了确定Spo 14 p产生的PA是否通过Arf-GAP介导其生物反应，我们分析了五种已知和潜在的酵母Arf-GAP中每一种缺失的细胞的孢子形成效率。只有gcs 1 Δ突变体显示出类似于spo 14突变体的孢子形成缺陷：缺失Gcs 1的细胞启动孢子形成程序，但在前孢子膜的合成中有缺陷。胞内体到液泡的运输也在孢子形成过程中受损。此外，Arf-GAP催化活性，而不是普列克底物蛋白同源结构域，是所需的原孢子膜形成和内体到液泡运输。对Gcs 1 p-绿色荧光蛋白的检查表明它是一种可溶性蛋白。有趣的是，缺失GCS 1的细胞具有减少的Spo 14 p产生的PA水平。综上所述，这些结果表明GCS 1是孢子形成所必需的，并表明GCS 1正调控SPO 14。
SPO14, encoding the majorSaccharomyces cerevisiaephospholipase D (PLD), is essential for sporulation and mediates synthesis of the new membrane that encompasses the haploid nuclei that arise through meiotic divisions. PLD catalyzes the hydrolysis of phosphatidylcholine to phosphatidic acid (PA) and choline. PA stimulates Arf-GTPase-activating proteins (Arf-GAPs), which are involved in membrane trafficking events and actin cytoskeletal function. To determine if Spo14p-generated PA mediates its biological response through Arf-GAPs, we analyzed the sporulation efficiencies of cells deleted for each of the five known and potential yeast Arf-GAPs. Onlygcs1Δmutants display a sporulation defect similar to that ofspo14mutants: cells deleted forGCS1initiate the sporulation program but are defective in synthesis of the prospore membrane. Endosome-to-vacuole transport is also impaired ingcs1Δcells during sporulation. Furthermore, Arf-GAP catalytic activity, but not the pleckstrin homology domain, is required for both prospore membrane formation and endosome-to-vacuole trafficking. An examination of Gcs1p-green fluorescent protein revealed that it is a soluble protein. Interestingly, cells deleted forGCS1have reduced levels of Spo14p-generated PA. Taken together, these results indicate thatGCS1is essential for sporulation and suggest thatGCS1positively regulatesSPO14.