mRNAs encoding polarity and exocytosis factors are cotransported with the cortical endoplasmic reticulum to the incipient bud in Saccharomyces cerevisiae
mRNAs encoding polarity and exocytosis factors are cotransported with the cortical endoplasmic reticulum to the incipient bud in Saccharomyces cerevisiae
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DOI：
10.1128/mcb.01643-06
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发表时间：
2007-05-01
影响因子：
5.3
通讯作者：
Gerst, Jeffrey E.
中科院分区：
文献类型：
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作者：
Aronov, Stella;Gelin-Licht, Rita;Gerst, Jeffrey E.
出芽酵母的极化生长取决于出芽前膜上极性和分泌因子的不对称定位和富集。我们研究了这些因子（即Cdc42， Sec4和Sro7）如何到达芽位点，发现它们各自的mrna在核分裂之前定位于初芽的尖端。不对称mRNA定位取决于促进ASH1 mRNA定位的因素（例如，3'非翻译区，She蛋白1至5，Puffi，肌动蛋白细胞骨架，以及与She2的物理关联）。mRNA放置先于蛋白质富集和随后的芽萌发，这意味着mRNA定位有助于极化。相应地，编码非对称分布的蛋白（即Snc1、Mso1、Tub1、Pex3和Oxa1）的mrna不会极化。最后，影响皮层内质网（ER）进入和在芽中锚定的突变（myo4 Delta、sec3 Delta和srp101）也会影响mRNA的不对称定位。芽定位mrna，包括ASH1，被发现以依赖She2和sec3的方式与ER微粒体收缩；因此，在酵母中，不对称mRNA转运和皮质内质网遗传是相互关联的。
Polarized growth in the budding yeast Saccharomyces cerevisiae depends upon the asymmetric localization and enrichment of polarity and secretion factors at the membrane prior to budding. We examined how these factors (i.e., Cdc42, Sec4, and Sro7) reach the bud site and found that their respective mRNAs localize to the tip of the incipient bud prior to nuclear division. Asymmetric mRNA localization depends upon factors that facilitate ASH1 mRNA localization (e.g., the 3' untranslated region, She proteins 1 to 5, Puffi, actin cytoskeleton, and a physical association with She2). mRNA placement precedes protein enrichment and subsequent bud emergence, implying that mRNA localization contributes to polarization. Correspondingly, mRNAs encoding proteins which are not asymmetrically distributed (i.e., Snc1, Mso1, Tub1, Pex3, and Oxa1) are not polarized. Finally, mutations which affect cortical endoplasmic reticulum (ER) entry and anchoring in the bud (myo4 Delta, sec3 Delta, and srp101) also affect asymmetric mRNA localization. Bud-localized mRNAs, including ASH1, were found to cofractionate with ER microsomes in a She2- and Sec3-dependent manner; thus, asymmetric mRNA transport and cortical ER inheritance are connected processes in yeast.