Tsai Kuo-Wang, Tarn Woan-Yuh, Lin Wen-Chang
Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan, Republic of China.
Mol Cell Biol. 2007 Aug;27(16):5835-48. doi: 10.1128/MCB.00363-07. Epub 2007 Jun 11.
Alternative splicing involving the 3' tandem splice site NAGNAG sequence may play a role in the structure-function diversity of proteins. However, how 3' tandem splice site utilization is determined is not well understood. We previously demonstrated that 3' NAGNAG-based wobble splicing occurs mostly in a tissue- and developmental stage-independent manner. Bioinformatic analysis reveals that the nucleotide preceding the AG dinucleotide may influence 3' splice site utilization; this is also supported by an in vivo splicing assay. Moreover, we found that the intron sequence plays an important role in 3' splice site selection for NAGNAG wobble splicing. Mutations of the region between the branch site and the NAGNAG 3' splice site, indeed, affected the ratio of the distal/proximal AG selection. Finally, we found that single nucleotide polymorphisms around the NAGNAG motif could affect the splice site choice, which may lead to a change in mRNA patterns and influence protein function. We conclude that the NAGNAG motif and its upstream region to the branch point sequence are required for 3' tandem splice site selection.
涉及3'串联剪接位点NAGNAG序列的可变剪接可能在蛋白质的结构-功能多样性中发挥作用。然而,3'串联剪接位点的使用是如何确定的,目前还不太清楚。我们之前证明基于3' NAGNAG的摆动剪接大多以与组织和发育阶段无关的方式发生。生物信息学分析表明,AG二核苷酸之前的核苷酸可能会影响3'剪接位点的使用;体内剪接试验也支持这一点。此外,我们发现内含子序列在NAGNAG摆动剪接的3'剪接位点选择中起重要作用。实际上,分支位点与NAGNAG 3'剪接位点之间区域的突变会影响远端/近端AG选择的比例。最后,我们发现NAGNAG基序周围的单核苷酸多态性可能会影响剪接位点的选择,这可能导致mRNA模式的改变并影响蛋白质功能。我们得出结论,3'串联剪接位点的选择需要NAGNAG基序及其到分支点序列的上游区域。