SALM synaptic cell adhesion-like molecules regulate the differentiation of excitatory synapses.
Synaptic cell adhesion molecules (CAMs) are known to play key roles in various aspects of synaptic structures and functions, including early differentiation, maintenance, and plasticity. We herein report the identification of a family of cell adhesion-like molecules termed SALM that interacts with the abundant postsynaptic density (PSD) protein PSD-95. SALM2, a SALM isoform, distributes to excitatory, but not inhibitory, synaptic sites. Overexpression of SALM2 increases the number of excitatory synapses and dendritic spines. Mislocalized expression of SALM2 disrupts excitatory synapses and dendritic spines. Bead-induced direct aggregation of SALM2 results in coclustering of PSD-95 and other postsynaptic proteins, including GKAP and AMPA receptors. Knockdown of SALM2 by RNA interference reduces the number of excitatory synapses and dendritic spines and the frequency, but not amplitude, of miniature excitatory postsynaptic currents. These results suggest that SALM2 is an important regulator of the differentiation of excitatory synapses.
Ko
Jaewon
J
National Creative Research Initiative Center for Synaptogenesis and Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Korea.
Kim
Seho
S
Chung
Hye Sun
HS
Kim
Karam
K
Han
Kihoon
K
Kim
Hyun
H
Jun
Heejung
H
Kaang
Bong-Kiun
BK
Kim
Eunjoon
E
D000818:Animals; D015152:Blotting, Northern; D001921:Brain / Q000502:physiology*; D002478:Cells, Cultured; D049229:Dendritic Spines / Q000378:metabolism*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D017403:In Situ Hybridization; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D019006:Neural Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism*; D009473:Neuronal Plasticity / Q000502:physiology*; D018408:Patch-Clamp Techniques; D020033:Protein Isoforms / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D013569:Synapses / Q000378:metabolism*; D014162:Transfection
D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D019006:Neural Cell Adhesion Molecules; D020033:Protein Isoforms; D012333:RNA, Messenger