Huggins Hayden P, Keiper Brett D
Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, NC, United States.
Front Cell Dev Biol. 2020 Jul 7;8:562. doi: 10.3389/fcell.2020.00562. eCollection 2020.
Translational regulation of mRNAs is critically important for proper gene expression in germ cells, gametes, and embryos. The ability of the nucleus to control gene expression in these systems may be limited due to spatial or temporal constraints, as well as the breadth of gene products they express to prepare for the rapid animal development that follows. During development germ granules are hubs of post-transcriptional regulation of mRNAs. They assemble and remodel messenger ribonucleoprotein (mRNP) complexes for translational repression or activation. Recently, mRNPs have been appreciated as discrete regulatory units, whose function is dictated by the many positive and negative acting factors within the complex. Repressed mRNPs must be activated for translation on ribosomes to introduce novel proteins into germ cells. The binding of eIF4E to interacting proteins (4EIPs) that sequester it represents a node that controls many aspects of mRNP fate including localization, stability, poly(A) elongation, deadenylation, and translational activation/repression. Furthermore, plants and animals have evolved to express multiple functionally distinct eIF4E and 4EIP variants within germ cells, giving rise to different modes of translational regulation.
mRNA的翻译调控对于生殖细胞、配子和胚胎中的基因正确表达至关重要。由于空间或时间限制，以及它们为后续快速的动物发育所表达的基因产物的广度，细胞核在这些系统中控制基因表达的能力可能受到限制。在发育过程中，生殖颗粒是mRNA转录后调控的中心。它们组装并重塑信使核糖核蛋白（mRNP）复合物，以实现翻译抑制或激活。最近，mRNP被认为是离散的调控单元，其功能由复合物中许多正向和负向作用因子决定。被抑制的mRNP必须被激活才能在核糖体上进行翻译，从而将新的蛋白质引入生殖细胞。eIF4E与隔离它的相互作用蛋白（4EIP）的结合代表了一个控制mRNP命运多个方面的节点，包括定位、稳定性、多聚腺苷酸化延伸、去腺苷酸化以及翻译激活/抑制。此外，植物和动物已经进化到在生殖细胞中表达多种功能不同的eIF4E和4EIP变体，从而产生不同的翻译调控模式。
