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 transport »
 Electron Microscopy: Transport »

Transport

 

a.  The mRNA molecule is transported to the nuclear pore. Before the translocation through the nuclear pore begins, some proteins, for example the splicing components, disassociate from the mRNA.

b.   Export proteins bind to the mRNA and as a first step in the translocation, the mRNA docks with the cage-like structure of the nuclear pore complex.
export proteins »
nuclear pore complex »

c.  The mRNA is translocated through the nuclear pore with the 5' end, the CAP structure, in the lead. The translocation through the nuclear pore is an energy requiring process, but the mechanism for the transport is not known.

d.  When the mRNA arrives at the cytoplasmic side of the nuclear pore, even if parts of the RNA are still within the pore or on the nuclear side, many proteins disassociate from the mRNA. Among those are the export proteins which return to the nucleus. The mRNA is immediately ready for the next step:
translation »