1.转录产物的加工 hnrna 修饰 剪接 RNA编辑 53帽子 3尾巴 mrNA
1. 转录产物的加工 hnRNA 修饰 剪接 RNA编辑 mRNA 5’帽子 3’尾巴
5′末端帽结构 R =P0-P-0 7mGpppNmpN 0-cH tve iNI 帽子0帽子帽子I
OCH3 帽子0 帽子I 帽子II
mRNA前体的剪接 Exon 1 Intron 1 Exon 2 Intron 2 Exon 3 DNA NMNA RNA Synthesis pre-mRNA Splicing removes introns mRNA
mRNA前体的剪接
5 splice site 3’ splice site PRE-mRNA snRNP snRNP Cap( Exon 1 Exon 2 AAAAA Lariat forms SPLICEOSOME 5'exon is FORMS cleaved Exon 1 Ex on 2 AAAAA Spliceosome Exon 1 Exon 2 3 MATURE MRNA Spliceosome 3 exon cleaves and splices with the 5 exon Exon 1 Exon 2 AAAAA 5 in will Translation be degraded
<1 min Trans caption starts: 5 end is modified 6 min 3 end of m RNA is released by cleavage 20 min 3 end is polyadeny lated eppa AAAAAA 25 min m RNA is transported to cytoplasm >4 hr Ribosomes translate mRNA AAAAA