Imagine that you are a cellular biologist studying the processing of a lysosomal
ID: 165452 • Letter: I
Question
Imagine that you are a cellular biologist studying the processing of a lysosomal protein. When you mutate a specific amino acid in its sequence, the protein accumulates in the trans cisternae of the Golgi complex and is NOT transported to the lysosome. What is a possible cause of this? Imagine that you are a cellular biologist studying the processing of a lysosomal protein. When you mutate a specific amino acid in its sequence, the protein accumulates in the trans cisternae of the Golgi complex and is NOT transported to the lysosome. What is a possible cause of this? a. The cells lack an enzyme to phosphorylate mannose residues. b. The mutation has created an ER retrieval tag. c. A glycosylation site has been removed.
Explanation / Answer
Answer a. The cells lack an enzymes to phosphorylate mannose residues.
In the golgi apparatus,phosphorylation of mannose units on lysosomal protein results in the formation of mannose 6 phosphate residue.This residue distinguishes lysosomal protein from other proteins and delivers them to the lysosome.In the absence of posphorylation mammose 6 phosphate residues won't be formed and the lysosomal protein wont be transported to the lysosome.