Studying the expression of a transcription regulatory protein in two cell types, you have performed experiments showing that the mRNA encoding the protein is present at comparable levels in the cytosol of both cell types. However, based on the expression of its target genes, you suspect that the protein activity might be significantly different in the two cell types. Which of the following steps in expression of the gene encoding this protein is more likely to be differentially controlled in these cell types?

a. Translation

b. mRNA transport

c. mRNA degradation

d. Transcription

a) option is correct

Explanation:

Since the mRNA levels are similar in both cell types, difference in protein activity can be attributed to differences in translation or in post-translational control

Translation is completed in four sequential steps: activation of amino acids (tRNA charging), initiation, elongation and termination

Eukaryotic translation is similar as prokaryotic translation but more complex due to: mRNA require preparation before translation, requirement of preparation of ribosomal small subunit require large number of initiation factors and require scanning of initiation codon