Question

In your biotechnology class your team is given the project of increasing the life span of an agriculturally important organism. Your team-mate suggests feeding the organism a drug that inhibits the proteasome, because protein degradation is wasteful of energy, and if we could reduce protein degradation then protein accumulation, growth, and life span would be enhanced. Given what you know about how cells handle proteins, is this likely to be a good approach to increasing longevity?

Only one answer is correct.

Question 4 options:

	yes, considerable energy is expended in making a polypeptide, so inhibiting protein degradation should increase longevity.
	yes, because if the proteasome were non-functional then poly-ubiquitin chains would likely be retained on ubiquitin ligase-targeted proteins and would contribute further to growth.
	no, because protein quality control is vital to cellular health and damaged/misfolded protein degradation through the proteasome is a key part of that quality control.
	no, because the proteasome would degrade any drug to which it was exposed.
	no, because if the proteasome cannot degrade proteins, it will degrade DNA, which would be lethal.

Answer 1

Proteasomes are protein complexes which degrade unneeded and damaged proteins by the process of proteolysis. Now, from a cell's perspective, it is very important for the cell to degrade unneeded proteins or other materials because degradation will provide the raw materials needed for various bio-molecule synthesis. Also, increased proteasome activity has been observed in long lived laboratory models. Thus, hyer proteasome activity can be positively co-related with the increased life span of organisms.

Now, if we inhibit the proteasome function by any inhibitor, the life span of the organism will decrease.

Thus, the option 'no, because protein quality control is vital to cellular health and damaged/misfolded protein degradation through the proteasome is a key part of that quality control.' is correct.

Thank you.

Happy Chegging!