title: Localization of the Diaphanous-related formin Daam1 to neuronal dendrites.
abstract: The Rho family of small GTPase proteins are involved in the formation and maintenance of neuronal dendrites. In this study, we show that Daam1, a member of the Diaphanous-related formin protein family and a downstream effector for RhoA, is localized to the dendrites of hippocampal neurons. Immunoblot analysis showed that Daam1 is enriched in the mouse hippocampus and co-fractionates in brain lysates with dendritic and synaptic proteins. Immunohistochemical analysis revealed that Daam1 protein distributes in a punctate pattern throughout the cell body and dendritic shafts of dissociated hippocampal neurons and organotypic hippocampal cultures. Although Daam1 is mostly expressed in the shaft of dendrites, co-stainings with SV2 or PSD95 revealed that Daam1 is also present at some synapses. In addition, viral directed expression of a fluorescently tagged Daam1 fusion protein in hippocampal slices resulted in targeted delivery to the dendrites of pyramidal neurons, leading to a reduction in the density of spines.
authors.affiliation: Center for Research in Neuroscience, McGill University Health Centre Research Institute, McGill University, Montreal, Quebec, Canada.
authors.forename: Steven N
authors.initials: SN
authors.lastname: Salomon
authors.forename: Michael
authors.initials: M
authors.lastname: Haber
authors.forename: Keith K
authors.initials: KK
authors.lastname: Murai
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Dunn
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002478:Cells, Cultured; D003712:Dendrites / Q000378:metabolism* / Q000648:ultrastructure; D049229:Dendritic Spines / Q000378:metabolism; D000076122:Disks Large Homolog 4 Protein; D004622:Embryo, Mammalian; D005786:Gene Expression Regulation; D051528:Guanylate Kinases; D006624:Hippocampus / Q000166:cytology; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D008840:Microfilament Proteins / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009474:Neurons / Q000166:cytology*; D009924:Organ Culture Techniques; D014162:Transfection; D020741:rho GTP-Binding Proteins / Q000378:metabolism*
chemical_list: D000076122:Disks Large Homolog 4 Protein; C501447:Dlg4 protein, mouse; D047908:Intracellular Signaling Peptides and Proteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D008840:Microfilament Proteins; D009419:Nerve Tissue Proteins; C489614:Sv2a protein, mouse; D051528:Guanylate Kinases; C500365:Daam1 protein, mouse; D020741:rho GTP-Binding Proteins