Biosynthesis of brain cytoplasmic 200 RNA

Youngmi Kim,Heegwon Shin,Seonghui Jang,Sun Chang Kim,Younghoon Lee,Jungmin Lee

doi:10.1038/s41598-017-05097-3

Youngmi Kim, Heegwon Shin + Show 4 more

Open Access

https://doi.org/10.1038/s41598-017-05097-3

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Abstract

Brain cytoplasmic 200 RNA (BC200 RNA), a neuron-specific non-coding RNA, is also highly expressed in a number of tumors of non-neuronal origin. However, the biosynthesis of BC200 RNA remains poorly understood. In this study, we show that the efficient transcription of BC200 RNA requires both internal and upstream promoter elements in cancer cells. The transcription complex seems to interact with a broad range of sequences within the upstream 100-bp region. The cellular levels and half-lives of BC200 RNA were found to differ across various cancer cell types, but there was no significant correlation between these parameters. Exogenously expressed BC200 RNA had a shorter half-life than that observed for the endogenous version in cancer cells, suggesting that BC200 RNA might be protected by some limiting factor(s) in cancer cells. Transient transfection experiments showed that the transcriptional activity of the exogenous BC200 RNA promoter element varied depending on the cancer cell type. However, the promoter activities together with the half-life data could not explain the differences in the levels of BC200 RNA among different cell types, suggesting that there is another level of transcriptional regulation beyond that detected by our transient transfection experiments.

Highlights

The biosynthesis of BC200 RNA is poorly understood
When the whole upstream sequence was deleted, the transcription dropped to less than 10% of the value from the −1010 nt construct. These results suggest that the −100 nt upstream sequence is important for BC200 RNA transcription and that the transcription complex interacts with a broad region of the upstream sequence
We found that exogenous expression was decreased by the TBPknockdown even when the TATA-like sequence was mutated, suggesting that the TATA-like sequence may not be essential for TATA binding protein (TBP) binding it contributes to the transcription efficiency

Summary

OPEN Biosynthesis of brain cytoplasmic

Youngmi Kim[1], Jungmin Lee[1], Heegwon Shin[1], Seonghui Jang[1], Sun Chang Kim2 & Younghoon Lee[1]. We show that the efficient transcription of BC200 RNA requires both internal and upstream promoter elements in cancer cells. Transient transfection experiments showed that the transcriptional activity of the exogenous BC200 RNA promoter element varied depending on the cancer cell type. The promoter activities together with the half-life data could not explain the differences in the levels of BC200 RNA among different cell types, suggesting that there is another level of transcriptional regulation beyond that detected by our transient transfection experiments. The high cellular contents of BC200 RNA in some cancer cells are not due solely to increased pol III activity, suggesting that changes in BC200 RNA stability may contribute to the levels of this ncRNA. Our results may provide a molecular basis for the mechanistic links between aberrant BC200 expression and tumorigenesis

Results

Discussion

CTATGAAAG AATTT GAGAATAAGA GGCCGGGCGCGGTG

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