What is the Difference Between Cis and Trans Splicing

Thekey difference between cis and trans splicingis that cis splicing is an intramolecular mechanism that removesintronsand joins theexonsthat are within the same RNA transcript, while trans-splicing is an intermolecular mechanism that removes introns or outrons and joins the exons that are not within the same RNA transcript.

RNA splicing is a form of RNA processing before蛋白质合成. In this process, a newly made预上音符RNAtranscript is transformed into a mature messenger RNA. Mature messenger RNA helps to produce a protein molecule. During RNA splicing, the introns (non-coding regions) are removed, and exons (coding regions) are joined together to make mature mRNA. Cis and trans splicing are two types of RNA splicing mechanisms.

内容

1.Overview and Key Difference
2.什么是顺式剪接
3.What is Trans Splicing
4.Similarities – Cis and Trans Splicing
5.Cis vs Trans Splicing in Tabular Form
6。Summary – Cis vs Trans Splicing

什么是顺式剪接？

顺式剪接是一种分子内机制，可去除内含子并连接在相同RNA转录本内的外显子。正常的顺式剪接过程单个RNA分子。顺式剪接是由剪接体进行的典型PRE mRNA的典型剪接过程。在内含子中，供体部位（内含子的5'末端），分支部位（内含子的3'末端）和受体位点（内含子的3'末端）对于剪接非常重要。接头供体网站包括内含子5'端的不变序列GU。内含子3'末端的剪接受体位点具有不变的Ag序列。在AG序列上游，有一个称为嘧啶区（polypyrimidine with）的区域。从息肉嘧啶道的上游进一步，有一个包括腺苷核苷酸的分支点。该核苷酸参与圈形的形成。

Figure 01: Cis and Trans Splicing

The major spliceosomes are U1, U2, U4, U5 and U6. Among them, U1 and U2 are very important. In cis splicing, the U1 binds to the 5’ splice site, and U2 binds to the branch point near the 3’ splice site. U5/U4/U6 binds exons at the 5’ site, with U6 binding to U2. Later, U1 is released. U5 shifts from exon to intron, and U6 binds at the 5’ splice site. Furthermore, U4 is also released. U6/U2 catalyzes transesterification, making the 5’ end of the intron ligate to the A nucleotide on intron. This triggers lariat formation. In the formation of a lariat, U5 binds exon at 3’ splice site, and the 5’ site is cleaved. At the final phase of splicing, U2/U5/U6 remain bound to the lariat, and 3’ site is cleaved. In addition to that, the exons are ligated using ATP hydrolysis in this phase.

What is Trans Splicing?

Trans splicing is an intermolecular mechanism that removes introns or outrons and joins the exons that are not within the same RNA transcript. In trans-splicing, there is no 5’ splice site on the pre mRNA molecule for U1 protein to bind. Instead, capped splice leader (SL) RNA is trans-spliced on to sequence in the outron.

Cis and Trans Splicing - Side by Side Comparison

Figure 02: Trans Splicing

Outron is a region of the pre mRNA between the 5’ cap and the trans splice site. However, U2 protein binds to the 3’ splice site usually. After removing outron, the splice leader (SL) exon is spliced to the first exon on the pre mRNA. Furthermore, trans-splicing is a mechanism that is observed in certain microorganisms such as protists of Kinetoplastae class to express genes.

顺式和反剪接之间有什么相似之处？

Cis and trans splicing are two types of RNA splicing mechanisms.
In both mechanisms, introns are removed.
肌萎缩性侧索硬化症o, in both mechanisms, exons are joined to form mature mRNA.
两种机制都在真核生物中发现。
这些机制在原核生物中不存在。