TRANSLATION REPRESSOR, 4E-BP2, IS COVALENTLY MODIFIED IN THE MAMMALIAN BRAIN

翻译抑制子 4E-BP2 在哺乳动物大脑中被共价修饰

• 批准号: 7359118
• 负责人: NAHUM SONENBERG
• 金额: $ 2.1万
• 依托单位: BATTELLE PACIFIC NORTHWEST LABORATORIES
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-01 至 2007-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7359118
• 关键词: TRANSLATION; REPRESSOR; 4E; BP2; COVALENTLY

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The eIF4E-binding proteins (4E-BPs) are a family of three conserved polypeptides that inhibit translation by binding to and sequestering the mRNA 5¿ cap binding protein, eIF4E. Binding of 4E-BPs to eIF4E is normally regulated by phosphorylation: hypophosphorylated 4E-BPs bind strongly to eIF4E, whereas hyperphosphorylated isoforms do not. The 4E-BPs are differentially expressed in mouse tissues such that 4E-BP2 is highly enriched in brain. Concordant with this, our laboratory has shown that 4E-BP2 plays an important role in learning and memory in mice. Two-dimensional isoelectric focusing/SDS-polyacrylamide gel electrophoresis of a mixture of protein extracts from brain and cultured mouse embryonic fibroblasts (MEFs) revealed that the brain-derived 4E-BP2 isoforms diverge from those corresponding to multiple phosphorylation events in MEFs. Unlike 4E-BP2 from cultured cells, brain-derived 4E-BP2 is also resistant to phosphatase treatment. These findings suggest that 4E-BP2 in brain is subject to different or additional posttranslational modifications (PTMs) than phosphorylation. Furthermore, these modifications show developmental regulation: the slowest migrating of the three 4E-BP2 isoforms is not present in the brain until postnatal day 15 and subsequently persists into adulthood. It is therefore of biochemical, neurobiological, and developmental interest to identify these modifications. A ¿top-down¿ mass spectrometric approach employing 12T FTICR mass spectrometer equipped with electron capture dissociation capability will be used to determine both the identity of the modifications and the amino acid sites of covalent attachment. These novel PTMs of 4E-BP2 may influence its binding to 4E; consequently, protein synthesis in the brain will be subject to an altered control mechanism. Subsequent analyses will compare the PTMs of adult brain 4E-BP2 with that of early postnatal brains (<15 days) to understand the changes that this protein undergoes during mammalian development.

该子项目是由NIH/NCRR资助的许多副标题之一。对于故事。结合蛋白EIF4E不会在小鼠组织中差异表达4E-BPS，因此4E-BP2高度富集在大脑中。和培养的小鼠胚胎拳（MEFS）S。与培养的细胞的4e-BP2不同，脑衍生的4e-BP2也对这些发现具有抗磷酸盐的抗性。与磷酸化相比，S显示出发育态度：在大脑中最慢，直到产后15次持续到成年后。自顶向下质谱批准的12T FTICR质谱仪电子捕获能力将确定共价附着的氨基酸位点的身份。更改控制机械的早期大脑（<15天），以了解蛋白质在Mamalian发育过程中发生的变化。