在PARP-1自动修改领域中识别ADP-ribosylation位点:分析和影响
Zhihua Tao1, Peng Gao, Hung-wen Liu
1Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas 78712, USA.
Journal of the American Chemical Society
|September 22, 2009
概括
研究人员在Poly(ADP-ribose) 聚合酶-1 (PARP-1) 的D域内确定了三个特定的ADP-ribosylation位点. 这项研究揭示了自动修饰发生在D域之外,并且D域对PARP-1酶活性不必.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 酶学 是一种酶学.
背景情况:
- 聚 ((ADP-ribose) 聚合酶-1 (PARP-1) 是一个关键的核蛋白,参与DNA修复和其他细胞过程.
- PARP-1 用NAD+作为基质来催化多ADP-ribosyl) 化,D域之前被认为是关键的相互作用和修饰部位.
研究的目的:
- 为了准确地确定PARP-1域D中的ADP-ribosylation位点.
- 调查PARP-1自动修饰的程度以及域D在其催化活性中的作用.
主要方法:
- 使用了一种PARP-1 E988Q突变体,以实现特定位点的ADP-ribosyl化.
- 采用素消化和液态染色学-并联质谱法 (LC-MS/MS) 进行ADP-ribosylation位点识别.
- 评估了缺乏域D的PARP-1突变体的催化活性.
主要成果:
- 在D域中确定了三个新的ADP-ribosylation位点:D387,E488和E491.
- 证明PARP-1自动修改扩展到D域之外,与之前的发现相反.
- 确认D域对于PARP-1催化活性是不可或缺的.
- 展示了来自D域的合成可以作为PARP-1基质.
结论:
- 建立了一个强大的方法来绘制PARP-1修改站点.
- 重新定义了对PARP-1自动修改站点的理解,以及域D的功能意义.
- 提供了对PARP-1催化机制和调节的未来研究的基础.
相关概念视频
Covalently Linked Protein Regulators
Proteins can undergo many types of post-translational modifications, often in response to changes in their environment. These modifications play an important role in the function and stability of these proteins. Covalently linked molecules include functional groups, such as methyl, acetyl, and phosphate groups, and also small proteins, such as ubiquitin. There are around 200 different types of covalent regulators that have been identified.
These groups modify specific amino acids in a protein.
These groups modify specific amino acids in a protein.
Protein Modifications in the RER
Modification of secretory and transmembrane proteins entering the rough ER begins in the ER lumen. These modifications aid in protein folding and stabilize the acquired tertiary structure. Protein modifications in the rough ER co-occur at different stages of protein folding.
Broadly, these modifications can be categorized into four main categories — glycosylation, formation of disulfide bonds, assembly of protein subunits, and specific proteolytic cleavages like removal of signal sequences.
Broadly, these modifications can be categorized into four main categories — glycosylation, formation of disulfide bonds, assembly of protein subunits, and specific proteolytic cleavages like removal of signal sequences.
RNA Editing
RNA editing is a post-transcriptional modification where a precursor mRNA (pre-mRNA) nucleotide sequence is changed by base insertion, deletion, or modification. The extent of RNA editing varies from a few hundred bases, in mitochondrial DNA of trypanosomes, to a just single base, in nuclear genes of mammals. Even a single base change in the pre-mRNA can convert a codon for one amino acid into the codon for another amino acid or a stop codon. This type of re-coding can significantly affect the...
Long-patch Base Excision Repair
Since the discovery of the two BER pathways, there has been a debate about how a cell chooses one pathway over the other and the factors determining this selection. Numerous in vitro experiments have pointed out multiple determinants for the sub-pathway selection. These are:


