NXF2 is involved in cytoplasmic mRNA dynamics through interactions with motor proteins.
Tap/NXF1, the founding member of the evolutionarily conserved NXF (Nuclear RNA export Factor) family of proteins, is required for the nuclear export of bulk poly(A)+ RNAs. In mice, three additional NXF family genes (NXF2, NXF3, NXF7) have been identified and characterized to date. Cumulative data suggest that NXF family members play roles, not only in nuclear mRNA export, but also in various aspects of post-transcriptional mRNA metabolism. In order to better understand the functional role of NXF2, we searched for its binding partners by yeast two-hybrid screening and identified several cytoplasmic motor proteins, including KIF17. The interaction of NXF2 with KIF17, which was confirmed by GST pull-down and co-immunoprecipitation assays, is mediated by the N-terminal domain of NXF2, which is required for the punctate localization patterns in dendrites of primary neurons. We also found that the NXF2-containing dendritic granules, which were co-localized with KIF17, mRNA and Staufen1, a known component of neuronal mRNA granules, moved bidirectionally along dendrites in a microtubule-dependent manner. These results suggest that NXF2, a nucleo-cytoplasmic mRNA transporter, plays additional roles in the cytoplasmic localization of mRNAs through interactions with cytoplasmic motor proteins.
Takano
Keizo
K
Department of Cell Biology and Neuroscience, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
Miki
Takashi
T
Katahira
Jun
J
Yoneda
Yoshihiro
Y
D000818:Animals; D002478:Cells, Cultured; D003593:Cytoplasm / Q000378:metabolism; D003712:Dendrites / Q000737:chemistry; D006624:Hippocampus / Q000166:cytology; D006801:Humans; D016547:Kinesins / Q000032:analysis / Q000378:metabolism; D051379:Mice; D020409:Molecular Motor Proteins / Q000032:analysis / Q000378:metabolism*; D009474:Neurons / Q000737:chemistry / Q000378:metabolism; D029543:Nucleocytoplasmic Transport Proteins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D017434:Protein Structure, Tertiary; D034443:RNA Transport; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley
C409642:KIF17 protein, mouse; D020409:Molecular Motor Proteins; D029543:Nucleocytoplasmic Transport Proteins; C502321:Nxf2 protein, mouse; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D016547:Kinesins