An RNA-interacting protein, SYNCRIP (heterogeneous nuclear ribonuclear protein Q1/NSAP1) is a component of mRNA granule transported with inositol 1,4,5-trisphosphate receptor type 1 mRNA in neuronal dendrites.
mRNA transport and local translation in the neuronal dendrite is implicated in the induction of synaptic plasticity. Recently, we cloned an RNA-interacting protein, SYNCRIP (heterogeneous nuclear ribonuclear protein Q1/NSAP1), that is suggested to be important for the stabilization of mRNA. We report here that SYNCRIP is a component of mRNA granules in rat hippocampal neurons. SYNCRIP was mainly found at cell bodies, but punctate expression patterns in the proximal dendrite were also seen. Time-lapse analysis in living neurons revealed that the granules labeled with fluorescent protein-tagged SYNCRIP were transported bi-directionally within the dendrite at approximately 0.05 microm/s. Treatment of neurons with nocodazole significantly inhibited the movement of green fluorescent protein-SYNCRIP-positive granules, indicating that the transport of SYNCRIP-containing granules is dependent on microtubules. The distribution of SYNCRIP-containing granules overlapped with that of dendritic RNAs and elongation factor 1alpha. SYNCRIP was also found to be co-transported with green fluorescent protein-tagged human staufen1 and the 3'-untranslated region of inositol 1,4,5-trisphosphate receptor type 1 mRNA. These results suggest that SYNCRIP is transported within the dendrite as a component of mRNA granules and raise the possibility that mRNA turnover in mRNA granules and the regulation of local protein synthesis in neuronal dendrites may involve SYNCRIP.
Bannai
Hiroko
H
Laboratory for Developmental Neurobiology, Brain Science Institute, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
Fukatsu
Kazumi
K
Mizutani
Akihiro
A
Natsume
Tohru
T
Iemura
Shun-Ichiro
S
Ikegami
Tohru
T
Inoue
Takafumi
T
Mikoshiba
Katsuhiko
K
D020413:3' Untranslated Regions; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D001692:Biological Transport; D015220:Calcium Channels / Q000737:chemistry*; D002478:Cells, Cultured; D003001:Cloning, Molecular; D003712:Dendrites / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D034441:Heterogeneous-Nuclear Ribonucleoproteins / Q000378:metabolism / Q000502:physiology*; D006624:Hippocampus / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D053496:Inositol 1,4,5-Trisphosphate Receptors; D018613:Microscopy, Confocal; D008870:Microtubules / Q000378:metabolism; D009474:Neurons / Q000378:metabolism*; D015739:Nocodazole / Q000494:pharmacology; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D020543:Proteome; D040901:Proteomics / Q000379:methods; D012313:RNA / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D018160:Receptors, Cytoplasmic and Nuclear / Q000737:chemistry*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013569:Synapses / Q000378:metabolism; D013997:Time Factors
D020413:3' Untranslated Regions; D000970:Antineoplastic Agents; D015220:Calcium Channels; D034441:Heterogeneous-Nuclear Ribonucleoproteins; C506926:ITPR1 protein, human; D053496:Inositol 1,4,5-Trisphosphate Receptors; D020543:Proteome; D012333:RNA, Messenger; D018160:Receptors, Cytoplasmic and Nuclear; D011993:Recombinant Fusion Proteins; C425312:SYNCRIP protein, human; D049452:Green Fluorescent Proteins; D012313:RNA; D015739:Nocodazole