Gene expression can occur at several points along the pathway from dna to rna proteins. in one example of gene expressions, the protein insulin must be trimmed to a smaller size. how is this an example of gene expression?

It is an example of gene expression and this type of proteins of a smaller size are known as hybrid proteins, they accumulate inside the bacterial cell

Explanation:

An example of this are chains A and B or what is known as proinsulin, which are released from the fusion protein through chemical methods for purification. When proteins A and B are isolated, they are subjected by a reaction to chemically rejoin. The product is active insulin.

Recovering bacterial cells is done by filtration. Then, the cells are broken so that they release the intracellular products. The protein of interest is recovered by differential centrifugation.