RNA剪接及调控机制 | RNA splicing and its regulation

核心概念

Splice Site (SS)

位于外显子与内含子的交界处，能够被剪接体（spliceosome）识别的内含子序列。

分为5'ss (donor site)、3'ss (acceptor site)。

5'ss中的5’指的是5'-intron

3'ss中的3’指的是3'-intron

Branching Point (BP)

位于内含子3'ss上游（50nt内）的部分保守序列，在剪接过程中能与5'ss结合形成分支。

Note. From “RNA Splicing by the Spliceosome,” by M. E. Wilkinson et al., 2019, Annual review of biochemistry, 89, p. 362.

RNA Splicing

剪接步骤

1. branching
2. ligation

剪接位点

Splicing Regulation

影响剪接的序列

包括：剪接核心保守序列（core consensus sequence）、剪接调节元件（splicing regulatory elements, SREs)

• 剪接核心保守序列：5'ss、3'ss、BP
• 剪接调节元件：增强或减弱剪接体与pre-mRNA序列结合 (i.e., acting on spliceosome recruitment)
  • exonic splicing enhancer (ESE)
  • exonic splicing silencer (ESS)
  • intronic splicing enhancer (ISE)
  • intronic splicing silencer (ISS)

调控方式

cis-acting 顺式作用、trans-acting 反式作用

• cis-regulation by
  • exonic splicing enhancer (ESE)
  • exonic splicing silencer (ESS)
  • intronic splicing enhancer (ISE)
  • intronic splicing silencer (ISS)
• trans-regulation by
  • SR proteins
  • hnRNPs