Plant J|Emb15编码质体核糖体装配因子，对玉米的胚发生至关重要
核糖体装配因子指导核糖体蛋白和核糖体RNA形成功能性核糖体的复杂过程。 然而，对植物质体核糖体的组装了解甚少。
在本研究中，我们基于对胚胎缺陷15（emb15）突变体的表征，发现了玉米（Zea mays）质体核糖体装配因子。 Emb15的功能丧失会在早期阶段延迟胚胎发育，但不会实质影响胚乳，并在其他遗传背景中引起白化病表型。
EMB15定位于质体，在N端具有核糖体成熟因子M（RimM）结构域，在C端具有预测的UDP-GlcNAc焦磷酸化酶（UAP）结构域。 EMB15 RimM结构域起源于细菌，UAP结构域起源于真菌； 在进化过程中，这两个领域是陆地植物的祖先。 EMB15的N端通过RimM缺失弥补了大肠杆菌菌株的生长缺陷，并挽救了emb15纯合突变体的白化表型。
RimM结构域介导EMB15和质体核糖体蛋白PRPS19之间的相互作用。 在emb15中，Plastid 16S rRNA的成熟也显着受损。
这些观察结果表明，EMB15在玉米种子发育中起质体核糖体装配因子的作用，在正常条件下C末端结构域并不重要。
Ribosome assembly factors guide the complex process by which ribosomal proteins and the ribosomal RNAs form a functional ribosome. However, the assembly of plant plastid ribosomes is poorly understood. In the present study, we discovered a maize (Zea mays) plastid ribosome assembly factor based on our characterization of the embryo defective 15 (emb15) mutant. Loss of function of Emb15 retards embryo development at an early stage, but does not substantially affect the endosperm, and causes an albino phenotype in other genetic backgrounds. EMB15 localizes to plastids and possesses a ribosome maturation factor M (RimM) domain in the N‐terminus and a predicted UDP‐GlcNAc pyrophosphorylase (UAP) domain in the C‐terminus. The EMB15 RimM domain originated in bacteria and the UAP domain originated in fungi; these two domains came together in the ancestor of land plants during evolution. The N‐terminus of EMB15 complemented the growth defect of an Escherichia coli strain with a RimM deletion and rescued the albino phenotype of emb15 homozygous mutants. The RimM domain mediates the interaction between EMB15 and the plastid ribosomal protein PRPS19. Plastid 16S rRNA maturation is also significantly impaired in emb15. These observations suggest that EMB15 functions in maize seed development as a plastid ribosome assembly factor, and the C‐terminal domain is not important under normal conditions.
https://onlinelibrary.wiley.com/doi/pdf/10.1111/tpj.15160?af=R
文章原创！转载请注明来源。
温馨提示：
为方便PaperRSS粉丝们科研、就业等话题交流。我们根据10多个专业方向（植物、医学、药学、人工智能、化学、物理、财经管理、体育等），特建立了30个国内外博士交流群。群成员来源欧美、日韩、新加坡、清华北大、中科院等全球名校。