Question

Which promoter is used for yeast cell expression?

• A. Polyhedrin
• B. Alcohol oxidase
• C. Cauliflower mosaic virus 35S
• D. T7 polymerase

Hint:

When working with yeast expression systems, promoters like alcohol oxidase offer high-level gene expression, especially under alcohol induction conditions.

Answer 1

The Correct Option is B

Alcohol oxidase is a promoter commonly used in yeast expression systems. It is often used in Saccharomyces cerevisiae for high-level gene expression, especially under conditions where alcohols such as methanol are present in the growth medium.

(1) Alcohol Oxidase:
- Alcohol oxidase promoter drives the expression of genes in yeast cells and is induced by alcohols, making it ideal for specific gene expression when alcohols are part of the medium.

(2) Why Other Options Are Incorrect:
- Polyhedrin (Option 1) is a promoter from the baculovirus expression system, used in insect cells, not yeast cells.
- Cauliflower mosaic virus 35S (Option 3) is used as a promoter in plant cells, not yeast.
- T7 polymerase (Option 4) is commonly used in bacterial systems like E. coli, not in yeast.

Conclusion: The alcohol oxidase promoter is commonly used in yeast cell expression systems, particularly in Saccharomyces cerevisiae.