Evidence that synaptotagmin is the Ca²⁺ sensor for exocytosis of neurotransmitters includes:
A)Ca²⁺ binding by synaptotagmin.
B)partial loss-of-function mutations of synaptotagmin in Drosophila and C.elegans that result in neurons that are defective in Ca²⁺-stimulated vesicle exocytosis.
C)uncoordinated embryonic muscle contractions in Drosophila and c.elegans mutants that lack synaptotagmin.
D)all of the above

Question

Quizplus · Accepted Answer

All of the given options are evidence that synaptotagmin is the Ca²⁺ sensor for exocytosis of neurotransmitters. Synaptotagmin binds Ca²⁺ and acts as a trigger for vesicle fusion, leading to release of neurotransmitters. Partial loss-of-function mutations of synaptotagmin in Drosophila and C.elegans result in defective Ca²⁺-stimulated vesicle exocytosis, indicating the importance of synaptotagmin in this process. Furthermore, mutants that lack synaptotagmin exhibit uncoordinated embryonic muscle contractions in Drosophila and C.elegans, further supporting the role of synaptotagmin as the Ca²⁺ sensor for exocytosis of neurotransmitters.

Evidence That Synaptotagmin Is the Ca²⁺ Sensor for Exocytosis of Neurotransmitters