Postsynaptic recruitment of Dendrin depends on both dendritic mRNA transport and synaptic anchoring.
Synaptic plasticity and memory formation involve remodeling of the postsynaptic cytoskeleton, a process that is in part based on both local translation of dendritic mRNAs and synaptic recruitment of newly synthesized proteins. The postsynaptic component Dendrin that is encoded by a dendritically localized mRNA is thought to modulate the structure of the synaptic cytoskeleton. However, molecular mechanisms that control extrasomatic Dendrin mRNA transport and postsynaptic protein recruitment are unknown. The data presented here reveal that Dendrin interacts with the cytoskeletal components alpha-actinin and Maguk with inverted orientation (MAGI) or synaptic scaffolding molecule (S-SCAM). The latter retains Dendrin in the cytoplasm of mammalian cells and prevents its nuclear import. Furthermore in neurons, postsynaptic clustering of Dendrin requires dendritic targeting of its messenger RNA (mRNA), a process that is mediated by a sequence motif within the 3' untranslated region. In summary our finding suggest that postsynaptic recruitment of Dendrin appears to critically depend on both local protein synthesis and association with the synaptic scaffolding protein MAGI/S-SCAM. Its nuclear localization capacity further points to a function in retrograde signaling from the synapse to the nucleus.
Kremerskothen
Joachim
J
Department for Experimental Tumorbiology, University Muenster, Badestrasse 9, D-48149 Muenster, Germany. kremers@uni-muenster.de
Kindler
Stefan
S
Finger
Indra
I
Veltel
Stefan
S
Barnekow
Angelika
A
D020413:3' Untranslated Regions / Q000502:physiology; D000185:Actinin / Q000378:metabolism; D021581:Active Transport, Cell Nucleus / Q000502:physiology; D048868:Adaptor Proteins, Signal Transducing; D020816:Amino Acid Motifs / Q000502:physiology; D000818:Animals; D001921:Brain / Q000378:metabolism* / Q000648:ultrastructure; D002352:Carrier Proteins / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D003599:Cytoskeleton / Q000378:metabolism*; D003712:Dendrites / Q000378:metabolism* / Q000648:ultrastructure; D051528:Guanylate Kinases / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D021381:Protein Transport / Q000502:physiology; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D015398:Signal Transduction / Q000502:physiology; D013570:Synaptic Membranes / Q000378:metabolism* / Q000648:ultrastructure; D009435:Synaptic Transmission / Q000502:physiology
D020413:3' Untranslated Regions; D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; C114103:Magi2 protein, rat; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; C104328:dendrin; D000185:Actinin; D051528:Guanylate Kinases; C508141:Magi1 protein, rat