Knockdown of pre-mRNA cleavage factor Im 25 kDa promotes neurite outgrowth.
Mammalian precursor mRNA (pre-mRNA) cleavage factor I (CFIm) plays important roles in the selection of poly(A) sites in a 3'-untranslated region (3'-UTR), producing mRNAs with variable 3' ends. Because 3'-UTRs often contain cis elements that impact stability or localization of mRNA or translation, alternative polyadenylation diversifies utilization of primary transcripts in mammalian cells. However, the physiological role of CFIm remains unclear. CFIm acts as a heterodimer comprising a 25kDa subunit (CFIm25) and one of the three large subunits-CFIm59, CFIm68, or CFIm72. CFIm25 binds directly to RNA and introduces and anchors the larger subunit. To examine the physiological roles of CFIm, we knocked down the CFIm25 gene in neuronal cells using RNA interference. Knockdown of CFIm25 increased the number of primary dendrites of developing hippocampal neurons and promoted nerve growth factor (NGF)-induced neurite extension from rat pheochromocytoma PC12 cells without affecting the morphology of proliferating PC12 cells. On the other hand, CFIm25 knockdown did not influence constitutively active or dominantly negative RhoA suppression or promotion of NGF-induced neurite extension from PC12 cells, respectively. Taken together, our results indicate that endogenous CFIm may promote neuritogenesis in developing neurons by coordinating events upstream of NGF-induced RhoA inactivation.
Laboratory of Molecular Biology, Department of Biofunctional Analysis, Gifu Pharmaceutical University, Daigakunishi 1-25-4, Gifu 501 1196, Japan. hfukumi@gifu-pu.ac.jp
Hidefumi
H
Fukumitsu
Hitomi
H
Soumiya
Shoei
S
Furukawa
D000818:Animals; D055785:Gene Knockdown Techniques; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology; D020932:Nerve Growth Factor / Q000494:pharmacology; D016501:Neurites / Q000187:drug effects / Q000502:physiology*; D016716:PC12 Cells; D059367:RNA Cleavage; D012322:RNA Precursors / Q000378:metabolism*; D051381:Rats; D039221:mRNA Cleavage and Polyadenylation Factors / Q000235:genetics / Q000502:physiology*; D020742:rhoA GTP-Binding Protein / Q000378:metabolism
D012322:RNA Precursors; C577493:cleavage factor Im, rat; D039221:mRNA Cleavage and Polyadenylation Factors; D020932:Nerve Growth Factor; D020742:rhoA GTP-Binding Protein