Role of Staufen in dendritic mRNA transport and its modulation.
Staufen is a double-stranded RNA-binding protein and a core component in various RNP complexes or RNA granules, and plays an important role in dendritic mRNA transport. In this study, a ribosomal marker and a dominant-negative form of Staufen (stau-RBD), containing the RNA-binding domains, but lacking a microtubule-association domain, was used to determine the role of Staufen in dendritic mRNA transport. The results showed that the overexpression of stau-RBD significantly decreased the levels of ribosomal staining in the dendrites, which was illustrated by Y10B immunostaining. In contrast, the overexpression of Staufen increased the ribosomal level. The regulatory mechanisms of the dendritic mRNA transport were examined using a GFP-tagged Staufen (GFP-Stau), which was produced by means of a Sindbis viral expression system. Depolarization increased the amount of Staufen-containing the RNP complexes and endogenous Staufen in the dendrites. This increase was independent of protein synthesis. This suggests that dendritic mRNA transport is mediated via Staufen, and is regulated by the neuronal activity.
Kim
Keun-Cheol
KC
Divison of Life Sciences, Kangwon National University, Chuncheon 200-701, Korea.
Kim
Hyong Kyu
HK
D000818:Animals; D000831:Animals, Newborn; D015153:Blotting, Western / Q000379:methods; D002478:Cells, Cultured; D003712:Dendrites / Q000187:drug effects / Q000378:metabolism*; D015870:Gene Expression / Q000187:drug effects / Q000502:physiology; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006624:Hippocampus / Q000166:cytology; D007150:Immunohistochemistry / Q000379:methods; D009474:Neurons / Q000166:cytology*; D011189:Potassium Chloride / Q000494:pharmacology; D034443:RNA Transport / Q000187:drug effects / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism*; D012335:RNA, Ribosomal / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000502:physiology*; D051381:Rats; D014162:Transfection / Q000379:methods
D005904:Glial Fibrillary Acidic Protein; D012333:RNA, Messenger; D012335:RNA, Ribosomal; D016601:RNA-Binding Proteins; C492186:Stau1 protein, rat; D049452:Green Fluorescent Proteins; D011189:Potassium Chloride