Piccolo modulation of Synapsin1a dynamics regulates synaptic vesicle exocytosis.
Active zones are specialized regions of the presynaptic plasma membrane designed for the efficient and repetitive release of neurotransmitter via synaptic vesicle (SV) exocytosis. Piccolo is a high molecular weight component of the active zone that is hypothesized to participate both in active zone formation and the scaffolding of key molecules involved in SV recycling. In this study, we use interference RNAs to eliminate Piccolo expression from cultured hippocampal neurons to assess its involvement in synapse formation and function. Our data show that Piccolo is not required for glutamatergic synapse formation but does influence presynaptic function by negatively regulating SV exocytosis. Mechanistically, this regulation appears to be calmodulin kinase II-dependent and mediated through the modulation of Synapsin1a dynamics. This function is not shared by the highly homologous protein Bassoon, which indicates that Piccolo has a unique role in coupling the mobilization of SVs in the reserve pool to events within the active zone.
Deptartment of Psychiatry and Behavioral Science, Nancy Pritzker Laboratory, Stanford University, Palo Alto, CA 94304, USA.
Sergio
S
Leal-Ortiz
Clarissa L
CL
Waites
Ryan
R
Terry-Lorenzo
Pedro
P
Zamorano
Eckart D
ED
Gundelfinger
Craig C
CC
Garner
D000818:Animals; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D005089:Exocytosis; D006624:Hippocampus / Q000196:embryology / Q000378:metabolism; D007700:Kinetics; D051379:Mice; D008954:Models, Biological; D009474:Neurons / Q000378:metabolism; D009479:Neuropeptides / Q000378:metabolism*; D018377:Neurotransmitter Agents / Q000378:metabolism; D017434:Protein Structure, Tertiary; D034741:RNA, Small Interfering / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013569:Synapses / Q000378:metabolism*; D016704:Synapsins / Q000378:metabolism*
D003598:Cytoskeletal Proteins; D009479:Neuropeptides; D018377:Neurotransmitter Agents; C405514:Pclo protein, rat; D034741:RNA, Small Interfering; D016704:Synapsins