Two Nucleolar Proteins, GDP1 and OLI2, Function As Ribosome Biogenesis Factors and Are Preferentially Involved in Promotion of Leaf Cell Proliferation without Strongly Affecting Leaf Adaxial-Abaxial Patterning in Arabidopsis thaliana.
Two Nucleolar Proteins, GDP1 and OLI2, Function As Ribosome Biogenesis Factors and Are Preferentially Involved in Promotion of Leaf Cell Proliferation without Strongly Affecting Leaf Adaxial-Abaxial Patterning in Arabidopsis thaliana.
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DOI：
10.3389/fpls.2017.02240
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发表时间：
2017
影响因子：
5.6
通讯作者：
Horiguchi G
中科院分区：
文献类型：
--
作者：
Kojima K;Tamura J;Chiba H;Fukada K;Tsukaya H;Horiguchi G
叶片背面-正面图案取决于正面或背面表达的叶片极性基因的相互抑制。在拟南芥中，这一过程受到核糖体蛋白基因和敏感遗传背景中核糖体生物发生基因突变的强烈影响，例如不对称叶2 (as2)。大多数核糖体相关突变体本身并不表现出叶片远轴化，并且它们的典型表型之一是形成尖形而不是圆形的叶片。在这项研究中，我们表征了两种核糖体相关突变体，以了解核糖体生物发生如何与叶片发育的几个方面相关。此前，我们分离出了oligocellula2 (oli2)，它表现出尖叶表型并具有细胞增殖缺陷。 OLI2 编码酿酒酵母中 Nop2 的同源物，这是一种参与 60S 前亚基成熟的核糖体生物发生因子。在这项研究中，我们发现了另一种尖叶突变体，该突变体在编码具有 G 补丁结构域的未表征蛋白质的基因中携带突变。与 oli2 类似，这种名为 g-patch 结构域蛋白 1 (gdp1) 的突变体的叶细胞数量减少。此外，gdp1 oli2 双突变体表现出强烈的遗传相互作用，从而协同损害叶片中的细胞增殖并产生明显更大的细胞。另一方面，当与几种已知的核糖体蛋白突变体结合时，它们表现出附加表型。此外，这些突变体在前 rRNA 加工中存在缺陷。 GDP1和OLI2在细胞增殖活性高的组织中强表达，并且GDP1-GFP和GFP-OLI2定位于核仁。这些结果表明 OLI2 和 GDP1 参与核糖体生物发生。然后，我们通过与 as2 杂交来检查 gdp1 和 oli2 对近轴-远轴图案化的影响。有趣的是，gdp1 和oli2 都没有强烈增强as2 的叶片极性缺陷。 as2 gdp1 oli2 三重突变体也获得了类似的结果，尽管它们表现出严重的生长缺陷。这些结果表明，核糖体相关突变诱导的叶片远轴化表型不仅仅是一般生长缺陷的结果，而且核糖体生物发生途径中可能存在一个敏感过程，当受到突变损害时，会影响近轴-远轴模式。
Leaf abaxial–adaxial patterning is dependent on the mutual repression of leaf polarity genes expressed either adaxially or abaxially. In Arabidopsis thaliana, this process is strongly affected by mutations in ribosomal protein genes and in ribosome biogenesis genes in a sensitized genetic background, such as asymmetric leaves2 (as2). Most ribosome-related mutants by themselves do not show leaf abaxialization, and one of their typical phenotypes is the formation of pointed rather than rounded leaves. In this study, we characterized two ribosome-related mutants to understand how ribosome biogenesis is linked to several aspects of leaf development. Previously, we isolated oligocellula2 (oli2) which exhibits the pointed-leaf phenotype and has a cell proliferation defect. OLI2 encodes a homolog of Nop2 in Saccharomyces cerevisiae, a ribosome biogenesis factor involved in pre-60S subunit maturation. In this study, we found another pointed-leaf mutant that carries a mutation in a gene encoding an uncharacterized protein with a G-patch domain. Similar to oli2, this mutant, named g-patch domain protein1 (gdp1), has a reduced number of leaf cells. In addition, gdp1 oli2 double mutants showed a strong genetic interaction such that they synergistically impaired cell proliferation in leaves and produced markedly larger cells. On the other hand, they showed additive phenotypes when combined with several known ribosomal protein mutants. Furthermore, these mutants have a defect in pre-rRNA processing. GDP1 and OLI2 are strongly expressed in tissues with high cell proliferation activity, and GDP1-GFP and GFP-OLI2 are localized in the nucleolus. These results suggest that OLI2 and GDP1 are involved in ribosome biogenesis. We then examined the effects of gdp1 and oli2 on adaxial–abaxial patterning by crossing them with as2. Interestingly, neither gdp1 nor oli2 strongly enhanced the leaf polarity defect of as2. Similar results were obtained with as2 gdp1 oli2 triple mutants although they showed severe growth defects. These results suggest that the leaf abaxialization phenotype induced by ribosome-related mutations is not merely the result of a general growth defect and that there may be a sensitive process in the ribosome biogenesis pathway that affects adaxial–abaxial patterning when compromised by a mutation.
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影响因子：
4.6
作者：
Casanova-Sáez R;Candela H;Micol JL
通讯作者：
Micol JL
影响因子：
7.3
作者：
Henras, Anthony K.;Plisson-Chastang, Celia;O'Donohue, Marie-Francoise;Chakraborty, Anirban;Gleizes, Pierre-Emmanuel
通讯作者：
Gleizes, Pierre-Emmanuel
影响因子：
10.5
作者：
Gamalinda M;Ohmayer U;Jakovljevic J;Kumcuoglu B;Woolford J;Mbom B;Lin L;Woolford JL Jr
通讯作者：
Woolford JL Jr
影响因子：
16
作者：
Grandi, P;Rybin, V;Hurt, E
通讯作者：
Hurt, E
影响因子：
7.2
作者：
Abbasi, Nazia;Kim, Ho Bang;Choi, Sang-Bong
通讯作者：
Choi, Sang-Bong