MBD2a-NuRD与甲基化γ-环球蛋白基因促进体结合,并独特地形成一个用于静止HbF表达所需的复合体
Shengzhe Shang1, Xia Li1,2, Alexander Azzo3,4
1Massey Cancer Center, Virginia Commonwealth University, Richmond, VA 23060.
概括
研究人员发现,MBD2-NuRD复合体通过阻断NF-Y与马环球蛋白基因促进体结合,使胎儿血红蛋白 (HbF) 沉默. 这种综合体涉及BCL11A和PRMT5,对于维持成人HbF沉默至关重要.
科学领域:
- 血液学 血液学 血液学
- 表观遗传学 在表观遗传学中,表观遗传学是指表观遗传学.
- 分子生物学分子生物学
背景情况:
- 胎儿血红蛋白 (HbF) 表达在出生后被沉默,这是正常发育至关重要的过程.
- 重新激活HbF显示了状细胞贫血的治疗潜力.
- BCL11A 和 MBD2-NuRD 是 HbF 沉默的关键因素.
研究的目的:
- 调查MBD2-NuRD在胎儿血红蛋白 (HbF) 沉默中的直接作用.
- 阐明MBD2-NuRD抑制马环球蛋白基因的分子机制.
- 为了确定MBD2-NuRD抑制器复合体内的特定组件和相互作用.
主要方法:
- 染色体免疫沉以评估在马环球蛋白基因促进体的MBD2-NuRD占用率.
- 核细胞定位测试用于确定染色体结构.
- 对MBD2a域 (MBD和GR) 的突变分析,以评估它们在复杂形成和基因沉默中的功能.
- 对PRMT5的招募试验和对基因组修饰的分析.
主要成果:
- MBD2-NuRD在成年红色素细胞中直接占据了马环球蛋白基因促进体,建立了一个封闭的染色体构造.
- MBD2a异型是与BCL11A和PRMT5.5形成抑制器复合物的必要条件.
- 马环球因子促进体和MBD2a甲基细胞因子结合域的甲基化对于高亲缘关系结合和沉默至关重要.
- MBD2a的GR域招募了PRMT5,导致H3K8me2s的压制性标记.
结论:
- 结合MBD2-NuRD,BCL11A和PRMT5,形成一个使胎儿血红蛋白 (HbF) 表达沉默的复合体.
- DNA甲基化和MBD2a的特定域对于这种抑制器复合物的招募和功能至关重要.
- 这些发现为HbF沉默提供了一个统一的模型,整合了表观遗传和基于蛋白质的机制.
相关概念视频
Master Transcription Regulators
7.0K
Master transcription regulators are regulatory proteins that are predominantly responsible for regulating the expression of multiple genes. Often these genes work in concert to drive a complex process. Activation of a master transcription regulator can lead to a cascade of transcriptional activation necessary for that outcome. These regulators can directly bind to the regulatory sequences of the various genes involved, or they can indirectly regulate transcription by binding to regulatory...
7.0K
Abnormal Proliferation
4.6K
Under normal conditions, most adult cells remain in a non-proliferative state unless stimulated by internal or external factors to replace lost cells. Abnormal cell proliferation is a condition in which the cell's growth exceeds and is uncoordinated with normal cells. In such situations, cell division persists in the same excessive manner even after cessation of the stimuli, leading to persistent tumors. The tumor arises from the damaged cells that replicate to pass the damage to the...
4.6K
Nonsense-mediated mRNA Decay
10.7K
The Upf proteins that carry out nonsense-mediated decay (NMD) are found in all eukaryotic organisms, including humans. Each protein has an individual role, but they need to work in collaboration. Upf1 is an ATP-dependent RNA helicase that unwinds the RNA helix. Because Upf1 can unwind any RNA, Upf2 and Upf3 are required to help Upf1 discriminate between nonsense and normal mRNAs.
Usually, Upf3 binds to an Exon Junction Complex (EJC) at mRNA splice sites. If a ribosome fully translates the mRNA,...
Usually, Upf3 binds to an Exon Junction Complex (EJC) at mRNA splice sites. If a ribosome fully translates the mRNA,...
10.7K
Heterochromatin
14.0K
The extent of chromatin compaction can be studied by staining chromatin using specific DNA binding dyes. Under the microscope, the dense-compacted regions that take up more dye are called heterochromatin. Heterochromatin is further classified into two forms – constitutive heterochromatin and facultative heterochromatin.
Constitutive heterochromatin: It is a highly compact region of chromatin that is mostly concentrated in the centromere and telomere. Unlike euchromatin, the amino acid at...
Constitutive heterochromatin: It is a highly compact region of chromatin that is mostly concentrated in the centromere and telomere. Unlike euchromatin, the amino acid at...
14.0K
NF-κB-dependent Signaling Pathway
7.5K
The transcription factor NF-κB was discovered in 1986 in the lab of Nobel laureate Professor David Baltimore, for its interaction with the immunoglobulin light chain enhancer in B-cells. After more than three decades of study, it is now evident that NF-κB regulates the expression of over 100 genes. Most of these genes play an essential role in the innate and adaptive immune responses as well as the inflammatory responses of animals.
NF-κB-dependent Signaling Mechanism
The...
NF-κB-dependent Signaling Mechanism
The...
7.5K
Hedgehog Signaling Pathway
7.4K
The Hedgehog gene (Hh) was first discovered due to its control of the growth of disorganized, hair-like bristles phenotype in Drosophila, much like hedgehog spines. Hh plays a crucial role in the development of organs and the maintenance of homeostasis in both invertebrates and vertebrates. However, while Drosophila has only one Hh protein, mammals have multiple functional Hedgehog proteins - Sonic (Shh), Desert (Dhh), and Indian Hedgehog (Ihh). All of these homologous proteins have adapted to...
7.4K


