Lariat-Intron

Term from genetics. A lariat intron is a special molecular structure that is formed during the splicing process in pre-mRNA transcription. Lariat intron refers to the form that an intron takes after it has been cut out of the pre-mRNA. The Lariat intron is a temporary structure that has an important function in the removal of non-coding sequences from the pre-mRNA. This particular structure contributes to the correct processing of the mRNA, which is required for subsequent protein production.

Main features and functions of the Lariat intron:

• Structure: The lariat looks like a closed ring or loop. The special loop structure is formed by a chemical reaction in which the 5' end of the intron is joined to a nucleotide inside the intron. This special connection is called the 2'-5' phosphodiester bond.
• Formation: The lariat is formed during the splicing process when the spliceosome processes the pre-mRNA. It cuts the intron at the acceptor and donor sites to form the lariat structure.

The formation of the lariat intron is a crucial step in the splicing process as it allows the spliceosome to efficiently remove the intron from the pre-mRNA. The lariat structure helps to isolate the intron from the exons.

Stability: A Lariat intron is usually degraded rapidly after it has been removed from the pre-mRNA. This degradation is important to ensure that the non-coding sequences do not enter the mature mRNA.

Regulation: The lariat form may also play a role in the regulation of splicing and gene expression. There is evidence that the way the spliceosome works and introns are removed is influenced by various cellular factors that may be involved in the formation of lariat structures.