一种新的KNL1内部拼接变体可能会破坏KMN复合物的稳定,导致一次性小头
Bridget J Fellows1, Giovanna Cantini Tolezano2, Sara Ferreira Pires2
1Department of Biochemistry, University of Otago, Dunedin, New Zealand.
American journal of medical genetics. Part A
|November 8, 2023
概括
在KNL1基因的遗传变异导致初级小头症 (MCPH). 在KNL1中,一种新的拼接变体破坏了动态基因,导致MCPH和兄弟姐妹的智力障碍.
科学领域:
- 遗传学 遗传学 是一个
- 分子生物学分子生物学
- 细胞生物学 细胞生物学
背景情况:
- 初级小头 (MCPH) 是一种神经发育障碍,其定义是头周长显著缩小.
- MCPH4与KNL1基因中的双变异有关,这是KMN网络的关键组成部分.
- 在细胞分裂 (线粒分裂) 过程中,KMN网络对于精确的染色体分离至关重要.
研究的目的:
- 研究来自非血缘家庭的两个兄弟姐妹的小头症和智力障碍的遗传原因.
- 识别和功能性描述与MCPH.相关的新型KNL1变异.
- 阐明MCPH中KNL1拼接变异的致病机制.
主要方法:
- 基因分析以确定受影响的兄弟姐妹中的KNL1变异.
- 在体外拼接测试以评估内基变异的影响.
- 定量PCR (qPCR) 用于测量转录水平.
- 蛋白质建模用于预测变种的结构和功能后果.
主要成果:
- 在兄弟姐妹中识别了复合异构KNL1变体 (一个框架转移和一个内在SNV).
- 已证实,内基变异会导致23号外子跳转,显著降低了正规KNL1转录水平.
- 蛋白质建模表明,缺少23号外子会破坏KMN网络相互作用和动态稳定性.
结论:
- 鉴定到的KNL1拼接变异是致病的,与移变异一起导致MCPH.
- 这项研究强调了拼接变异作为KNL1.1的重大致病突变类别.
- 这些发现扩大了对KNL1在神经发育和神经分裂中的作用的理解.
相关概念视频
Alternative RNA Splicing
21.2K
Alternative RNA splicing is the regulated splicing of exons and introns to produce different mature mRNAs from a single pre-mRNA. Unlike in constitutive splicing where a single gene produces a single type of mRNA, alternative splicing allows an organism to produce multiple proteins from a single gene and plays an important role in protein diversity.
There are five types of alternative RNA splicing that vary in the ways the pre-mRNA segments are removed or retained in the mature mRNA. The first...
There are five types of alternative RNA splicing that vary in the ways the pre-mRNA segments are removed or retained in the mature mRNA. The first...
21.2K
RNA Splicing
56.4K
Splicing is the process by which eukaryotic RNA is edited before its translation into protein. The RNA strand transcribed from eukaryotic DNA is called the primary transcript. The primary transcripts that become mRNAs are called precursor messenger RNAs (pre-mRNAs). Eukaryotic pre-mRNA contains alternating sequences of exons and introns. Exons are nucleotide sequences that code for proteins, whereas introns are the non-coding regions. In RNA splicing, introns are removed and exons are bonded...
56.4K
Nonsense-mediated mRNA Decay
10.6K
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,...
10.6K
Chromatin Structure Regulates pre-mRNA Processing
7.0K
In eukaryotic cells, nascent mRNA transcripts need to undergo many post-transcriptional modifications to reach the cell cytoplasm and translate into functional proteins. For a long time, transcription and pre-mRNA processing were considered two independent events that occur sequentially in the cell. However, it has now been well established that transcription and pre-mRNA processing are two simultaneous processes that are precisely regulated inside the cell.
The chromatin structure, especially...
The chromatin structure, especially...
7.0K
Exon Recombination
3.6K
The evolution of new genes is critical for speciation. Exon recombination, also known as exon shuffling or domain shuffling, is an important means of new gene formation. It is observed across vertebrates, invertebrates, and in some plants such as potatoes and sunflowers. During exon recombination, exons from the same or different genes recombine and produce new exon-intron combinations, which might evolve into new genes.
Exon shuffling follows “splice frame rules.” Each exon...
Exon shuffling follows “splice frame rules.” Each exon...
3.6K
Cytoskeletal Linker Proteins - Plakins
2.3K
Plakins are large proteins with binding domains for microtubules, microfilaments, intermediate filaments, and membrane-associated protein complexes at cell junctions. Plakin functions are evolutionarily conserved and are primarily involved in organizing the different components of the cytoskeleton by crosslinking them to each other and connecting them to the cell-matrix and cell adhesion complexes. They are also known to interact with signal transducers, serve as scaffolds for signaling...
2.3K


