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The following animation will describe the process of RNA splicing,

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an important step in creating the mRNA that is involved in protein synthesis

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via the process of translation.

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Key factors in this process include

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RNA, possessing introns and exons,

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and the spliceosome.

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Here we see an RNA molecule with a single intron.

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Several signals exist within the intron

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that are used in the splicing process.

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From the 5 prime end of the intron,

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these are GU, the A branch site, a pyrimidine-rich region,

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and the 3 prime AG.

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The GU and AG sequences define the beginning and end

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of the intron.

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Splicing is mediated by the spliceosome,

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which consists of several protein RNA complexes.

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The first step involves two complexes

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that bind near the GU sequence. The RNA is then looped and three other protein RNA complexes

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bind. This final complex then undergoes a conformational change.

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Introns are non-coding RNA sequences that must be removed before translation. The process

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of removing the intron is called splicing. The intron is then cleaved at the 5' GU sequence

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and forms a lariat at the A branch site.

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The three prime end of the intron

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is next cleaved at the AG sequence,

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and the two exons are ligated together.

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As the spliced mRNA is released from the spliceosome,

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the intron debranches and is then degraded.