Question

A transmembrane protein has its N-terminus in the lumen of the ER, its C-terminus in the cytoplasm, and it spans the membrane five times. What are all the signals that this protein displayed, including any that may have been cleaved? (In the following options "STS" stands for "stop transfer sequence")

Answer 1

Answer:

N-terminal signal sequence --> STS --> internal signal sequence --> STS --> internal signal sequence --> STS

Explanation:

Steroid Sulfatase (STS) is a signal localized in the endoplasmic reticulum, it catalyzes the desulfation reaction

N-Terminal is the protein domain that is outside of the cell membrane

The internal signal sequence directs the protein to the membrane of the endoplasmic reticulum, this signal is also responsible for open the membrane pore