help  | about  | cite  | software

Publication : Discrete residues in the c(2)b domain of synaptotagmin I independently specify endocytic rate and synaptic vesicle size.

First Author  Poskanzer Kira E Year  2006
Journal  Neuron Volume  50
Pages  49-62 PubMed ID  16600855
Abstract Text  It has been demonstrated that synapses lacking functional synaptotagmin I (Syt I) have a decreased rate of synaptic vesicle endocytosis. Beyond this, the function of Syt I during endocytosis remains undefined. Here, we demonstrate that a decreased rate of endocytosis in syt(null) mutants correlates with a stimulus-dependent perturbation of membrane internalization, assayed ultrastructurally. We then separate the mechanisms that control endocytic rate and vesicle size by mapping these processes to discrete residues in the Syt I C(2)B domain. Mutation of a poly-lysine motif alters vesicle size but not endocytic rate, whereas the mutation of calcium-coordinating aspartate residues (syt-D3,4N) alters endocytic rate but not vesicle size. Finally, slowed endocytic rate in the syt-D3,4N animals, but not syt(null) animals, can be rescued by elevating extracellular calcium concentration, supporting the conclusion that calcium coordination within the C(2)B domain contributes to the control of endocytic rate. Doi  10.1016/j.neuron.2006.02.021
Issue  1 Month  Apr

Publication Annotations Displayer

18 Entities

26 Mesh Terms