The mechanism of dynamin activity is not fully understood. There are two schools
ID: 62080 • Letter: T
Question
The mechanism of dynamin activity is not fully understood. There are two schools of thought on the matter. The first one suggests that the GTPase activity of dynamin allows dynamin to pinch off the neck of the vesicle. The other suggests that the GTP-bound form of dynamin acts as a signal to recruit other enzymes that actually do the pinching of the membrane. Since you are a cell biology stud, you decide to do an experiment to answer this question once-and-for-all. To do this, you prepare a mutated form of the dynamin gene that prevents it from hydrolyzing its bound GTP. You then perform an experiment where you express the mutated dynamin gene, along with the proper controls, in animal cells lacking a functional, endogenous dynamin gene and analyze the ability of those cells to form clathrin-coated vesicles. Answer the following questions using the data when necessary.
A. In what state is the mutant dynamin – active or inactive? In 2-3 sentences, explain why you chose that answer.
B. Which of the two schools of thought does the data support? USE THE DATA GIVEN to explain your answer in 2-3 sentences.
C. What would the data look like if the other school of thought was supported? Explain why in 2-3 sentences.
Cells expressing... Result wild-type dynamin + mutant dynamin + no dynamin -Explanation / Answer
Dynamin is a GTPase ,responsible for the endocytosis ,it is involved in the scission of the newly formed vesicle form the memberane from one cellular compartment to another compartment both at thecellular surface as well as a golgi apparatus . Dynamin forms a spiral around the neck of the vesicle , causes it to break and results in pinching off of the vesicle from parents memberane ,
a. Mutants dynamins ; they are inactive as there is no GTP hydrolysis , it cannot pinch off the vesicle
b. wild dynamics ; They are in active state as there is a GTP hydrolysis ,it can pinch off the vesicle .
c . no dynamics; they are is no dynamins .
the first schools has thought the correct about the GTP hydrolysis