Translation initiation is an important step in gene expression.
We will start with a general introduction,
and then we will illustrate the mechanism
of translation initiation in eukaryotes.
Using this knowledge, we will analyze the possible ways
of general regulation of translation initiation.
And finally, we will look at gene-specific regulation of translation initiation.
A few important concepts will guide us on our journey.
First, the control occurs, in general, at the level of initiation.
Second, general translational control of an implied modification of eIFs—
eukaryotic initiation factors—
or the competitive interaction of eIFs.
Interestingly, it is often the escape of general transcription control
that allows gene-specific regulation.
And finally, an important point in the control
is the inhibition of the scanning process.
The central dogma tells us that the flow of information
from DNA to RNA, and from RNA to protein—
the proteins, then, have different functions in the cell.
The regulation of gene expression can occur at the level of transcription,
translation, or at the post-translational level.
Translation is the synthesis of long chains of amino acids
by cellular machines called the ribosomes.
These ribosomes read the RNA 3 letters by 3 letters.
Three letters together represent one codon,
and every codon contains the information for one amino acid.