Question

If AT1 is a transmembrane protein, a mature AT1 mRNA is most likely to contain a sequence coding for which genetic factor(s)?

1) signal sequence
2) introns
3) promoter
4) nuclear localization signal

Answer 1

A mature AT1 mRNA, coding for a transmembrane protein, is most likely to contain a signal sequence that directs the protein to the cell membrane.

Step-by-step explanation:

If AT1 is a transmembrane protein, a mature AT1 mRNA is most likely to contain a sequence coding for a signal sequence, which is a short tail of amino acids that directs the protein to a specific cellular compartment. This sequence acts like a "train ticket" sending the protein to the proper location within the cell, such as the cell membrane. In contrast, introns would have been removed during RNA processing to form mature mRNA, promoters are located upstream of the transcription start site and are not transcribed into mRNA, and nuclear localization signals are sequences that direct proteins to the nucleus, which would not be relevant for a transmembrane protein such as AT1.