Abstract
The molecular mechanisms involved in neuronal/astroglial cell fate decisions during the development of the mammalian central nervous system are poorly understood. Here, we report that PRP19beta, a splice variant of mouse PRP19alpha corresponding to the yeast PRP19 protein, can function as a neuron-astroglial switch during the retinoic acid-primed neural differentiation of P19 cells. The beta-variant possesses an additional 19 amino acid residues in-frame in the N-terminal region of the alpha-variant. The forced expression of the alpha-variant RNA caused the down-regulation of oct-3/4 and nanog mRNA expression during the 12-48 h of the late-early stages of neural differentiation and was sufficient to convert P19 cells into neurons (but not glial cells) when the cells were cultured in aggregated form without retinoic acid. In contrast, the forced expression of the beta-variant RNA suppressed neuronal differentiation and conversely stimulated astroglial cell differentiation in retinoic acid-primed P19 cells. Based on yeast two-hybrid screening, cyclophilin A was identified as a specific binding partner of the beta-variant. Luciferase reporter assay mediated by the oct-3/4 promoter revealed that cyclophilin A could act as a transcriptional activator and that its activity was suppressed by the beta-variant, suggesting that cyclophilin A takes part in the induction of oct-3/4 gene expression, which might lead to neuroectodermal otx2 expression within 12 h of the immediate-early stages of retinoic acid-primed neural differentiation. These results show that the alpha-variant gene plays a pivotal role in neural differentiation and that the beta-variant participates in neuronal/astroglial cell fate decisions.
Highlights
IntroductionIn Drosophila, neuronal and glial fates are determined by the gcm ( glial cell missing) gene encoding a transcription factor as a binary switch [1]
In Drosophila, neuronal and glial fates are determined by the gcm gene encoding a transcription factor as a binary switch [1]
Isolation of Prp19␣ cDNA—To isolate the early response genes that participate in the retinoic acid (RA)-primed neural differentiation of mouse P19 cells, we employed a subtractive cDNA cloning strategy to enrich genes that are highly expressed in P19 cells after 24 h of RA treatment as described previously [16]
Summary
In Drosophila, neuronal and glial fates are determined by the gcm ( glial cell missing) gene encoding a transcription factor as a binary switch [1]. Recent studies have shown that the Sox transcription factor [13], the QKI RNA-binding protein [14], and extrinsic cues such as bone morphogenetic protein (BMP) and ciliary neurotrophic factor (CNTF) [15] promote the differentiation of neural progenitors into glia These limited factors may be insufficient for the regulation of glial cell differentiation because mammalian astrocytes exhibit a large heterogeneity, differing in morphology, distribution, molecular types expressed, function, and cell lineage. In this context, to clarify the molecular mechanisms in neuronal/ astroglial fate decisions in mammals, we applied a subtractive cDNA cloning strategy for the retinoic acid (RA)-induced neural differentiation system of mouse P19 embryonic carcinoma cells as described previously [16]. These results imply that the regulation of alternative splicing of the mouse Prp gene plays an important role in neuronal and astroglial cell fate decisions
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
