Editing Messenger RNA (section)

===Translation===
{{main|Translation (biology)}}
[[File:Peptide syn.svg|thumb|Translation of mRNA to protein]]
Because prokaryotic mRNA does not need to be processed or transported, translation by the [[ribosome]] can begin immediately after the end of transcription. Therefore, it can be said that prokaryotic translation is ''coupled'' to transcription and occurs ''co-transcriptionally''. <ref>{{cite journal | doi=10.3389/fmicb.2020.624830 | doi-access=free | title=Coupled Transcription-Translation in Prokaryotes: An Old Couple with New Surprises | date=2021 | journal=Frontiers in Microbiology | volume=11 | vauthors = Irastortza-Olaziregi M, Amster-Choder O | pmid=33552035 | pmc=7858274 }}</ref>

Eukaryotic mRNA that has been processed and transported to the cytoplasm (i.e., mature mRNA) can then be translated by the ribosome. Translation may occur at ribosomes free-floating in the cytoplasm, or directed to the [[endoplasmic reticulum]] by the [[signal recognition particle]]. Therefore, unlike in prokaryotes, eukaryotic translation ''is not'' directly coupled to transcription. It is even possible in some contexts that reduced mRNA levels are accompanied by increased protein levels, as has been observed for mRNA/protein levels of [[Eukaryotic translation elongation factor 1 alpha 1|EEF1A1]] in [[breast cancer]].<ref name=Lin2018>{{cite journal | vauthors = Lin CY, Beattie A, Baradaran B, Dray E, Duijf PH | title = Contradictory mRNA and protein misexpression of EEF1A1 in ductal breast carcinoma due to cell cycle regulation and cellular stress | journal = Scientific Reports | volume = 8 | issue = 1 | pages = 13904 | date = September 2018 | pmid = 30224719 | pmc = 6141510 | doi = 10.1038/s41598-018-32272-x | bibcode = 2018NatSR...813904L }}</ref>{{Primary source inline|date=June 2021}}