A dysfunctional cell lacks a signal peptidase and is unable to cleave the ER signal sequence from proteins translated in the ER.What will be the effect on the cell's proteins?
A)The cell will have no integral membrane proteins
B)All cellular proteins will have an ER signal sequence
C)There will be a common signal sequence at the N-terminus of all integral membrane proteins in the plasma membrane
D)All cellular proteins will become membrane proteins
E)There will be a common signal sequence at the C-terminus of all integral membrane proteins in the nuclear envelope

Question

Quizplus · Accepted Answer

Signal peptidase is responsible for cleaving the ER signal sequence from proteins once they are translocated into the ER. If this enzyme is dysfunctional, proteins that are normally processed in the ER and directed to the plasma membrane will retain their signal sequence at the N-terminus, leading to a common signal sequence at the N-terminus of all integral membrane proteins in the plasma membrane.

A Dysfunctional Cell Lacks a Signal Peptidase and Is Unable