FIGURE 3.

Hypothetical model of the potential involvement of methylation in mRNA transport. The transcribed mRNA is methylated by methyltransferase, which in turn mediates the transport of the mRNA from the nucleus to the cytoplasm. Methylation may reduce the translation ability of the mRNA until it reaches the target cell. RBP recognizes the motif near the methylation site to form an RNA-protein complex. Methylation is involved in regulating the size-exclusion limit of PD to carry out STS loading of mRNA and stabilize mRNA and its TLS in SE. Methylation is involved in identifying unloading locations and completing sieve element unloading of mRNA near the target cell. After reaching the target cell, mRNA reduces the methylation level under the action of demethylase and restores translation ability. The locations of yellow circles in the figure do not indicate the actual methylation sites, but the number of them indicates the level of methylation.