[Structure of nuclear pre-mRNA. XI. Triphosphorylated and blocked 5'-ends in the pre-mRNA].

Abstract

The nature of the 5'-termini in pre-mRNA isolated from Ehrlich carcinoma cells has been investigated. To discriminate between triphosphorylated 5'-ends and capped structures different methods were used including treatment by alkaline phosphatase and several chromatographic methods. It was shown that heavey pre-mRNA contains a significant number of non-blocked triphosphorylated nucleotides at the 5'-end termini. However, phosphatase resistent, blocked 5'-termini were also found. 5'-terminal nucleotides in triphosphorylated pre-mRNA are G in a 3 : 2 ratio. In contrast to nuclear pre-mRNA cytoplasmic poly(A)+mRNA does not contain triphosphorylated 5'-ends but does contain the "cap" structure only. To elucidate the pre-mRNA topography the localization of homopolymeric regions of pre-mRNA, poly(A) and oligo(U), in relation to 5'terminal structures has been investigated. The experiments showed that the distance between 3'-terminal poly(A) sequences and 5'-end triphosphates is longer than 1500--2000 nucleotides. At the same time the distance between the latter and oligo(U) in pre-mRNA is much shorter.

• Authors: O P Samarina, N I Peunova, D Boĭsar, G P Georgiev
• Journal: Molekuliarnaia biologiia (Mol Biol (Mosk)) 1979 Jan-Feb Vol. 13 Issue 1 Pg. 60-72 ISSN: 0026-8984 [Print] Russia (Federation)
• Vernacular Title: Struktura iadernoi pro-mRNK. XI. Trifosforilirovannye i blokirovannye 5'-kontsy v pro-mRNK.
• PMID: 460197 (Publication Type: English Abstract, Journal Article)

Chemical References

• RNA, Messenger
• Ribonucleotides
• Poly A
• Alkaline Phosphatase

Topics

• Alkaline Phosphatase
• Animals
• Carcinoma, Ehrlich Tumor (analysis)
• Cell Nucleus (analysis)
• Mice
• Phosphorylation
• Poly A (analysis)
• RNA, Messenger
• Ribonucleotides (analysis)