title: Piccolo Directs Activity Dependent F-Actin Assembly from Presynaptic Active Zones via Daam1.
abstract: The dynamic assembly of filamentous (F) actin plays essential roles in the assembly of presynaptic boutons, the fusion, mobilization and recycling of synaptic vesicles (SVs), and presynaptic forms of plasticity. However, the molecular mechanisms that regulate the temporal and spatial assembly of presynaptic F-actin remain largely unknown. Similar to other F-actin rich membrane specializations, presynaptic boutons contain a set of molecules that respond to cellular cues and trans-synaptic signals to facilitate activity-dependent assembly of F-actin. The presynaptic active zone (AZ) protein Piccolo has recently been identified as a key regulator of neurotransmitter release during SV cycling. It does so by coordinating the activity-dependent assembly of F-Actin and the dynamics of key plasticity molecules including Synapsin1, Profilin and CaMKII. The multidomain structure of Piccolo, its exquisite association with the AZ, and its ability to interact with a number of actin-associated proteins suggest that Piccolo may function as a platform to coordinate the spatial assembly of F-actin. Here we have identified Daam1, a Formin that functions with Profilin to drive F-actin assembly, as a novel Piccolo binding partner. We also found that within cells Daam1 activation promotes Piccolo binding, an interaction that can spatially direct the polymerization of F-Actin. Moreover, similar to Piccolo and Profilin, Daam1 loss of function impairs presynaptic-F-actin assembly in neurons. These data suggest a model in which Piccolo directs the assembly of presynaptic F-Actin from the AZ by scaffolding key actin regulatory proteins including Daam1.
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Nancy Pritzker Laboratory, Stanford University, Stanford, California, United States of America.
authors.forename: Dhananjay
authors.initials: D
authors.lastname: Wagh
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Nancy Pritzker Laboratory, Stanford University, Stanford, California, United States of America.
authors.forename: Ryan
authors.initials: R
authors.lastname: Terry-Lorenzo
authors.affiliation: Department of Pathology and Cell Biology Columbia University New York, New York, United States of America.
authors.forename: Clarissa L
authors.initials: CL
authors.lastname: Waites
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Nancy Pritzker Laboratory, Stanford University, Stanford, California, United States of America.
authors.forename: Sergio A
authors.initials: SA
authors.lastname: Leal-Ortiz
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Nancy Pritzker Laboratory, Stanford University, Stanford, California, United States of America.
authors.forename: Christoph
authors.initials: C
authors.lastname: Maas
authors.affiliation: Department of Neurology and Neurological Sciences Stanford University and Veterans Affairs Palo Alto Health Care System, Palo Alto, California, United States of America.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Reimer
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Nancy Pritzker Laboratory, Stanford University, Stanford, California, United States of America.
authors.forename: Craig C
authors.initials: CC
authors.lastname: Garner
mesh_terms: D000199:Actins / Q000378:metabolism*; D000818:Animals; D019556:COS Cells; D002462:Cell Membrane / Q000378:metabolism; D002522:Chlorocebus aethiops; D003598:Cytoskeletal Proteins / Q000737:chemistry / Q000502:physiology*; D005260:Female; D047908:Intracellular Signaling Peptides and Proteins / Q000737:chemistry / Q000378:metabolism*; D051379:Mice; D009479:Neuropeptides / Q000737:chemistry / Q000502:physiology*; D017729:Presynaptic Terminals / Q000378:metabolism*; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D055503:Protein Multimerization; D021381:Protein Transport; D011554:Pseudopodia / Q000378:metabolism; D017207:Rats, Sprague-Dawley; D022502:Stress Fibers / Q000378:metabolism
chemical_list: D000199:Actins; D003598:Cytoskeletal Proteins; C000606312:Daam1 protein, rat; D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; C405514:Pclo protein, rat