The ways of action of long non-coding RNAs in cytoplasm and nucleus.

Over the past fifteen years, small regulatory RNAs, such as siRNA and miRNA, have been extensively investigated and the underlying molecular mechanisms have been well documented, suggesting that ncRNAs play a major function in many cellular processes. An expanding body of evidence reveals that long non-coding RNAs (lncRNAs), once described as dark matter, are involved in diverse cellular progresses, including regulation of gene expression, dosage compensation, genomic imprinting, nuclear organization and nuclear-cytoplasm trafficking via a number of complex mechanisms. The emerging links between lncRNAs and diseases as well as their tissue-specific expression patterns also indicate that lncRNAs comprise a core transcriptional regulatory circuitry. The function of lncRNAs is based on their sequence and structure; and they can combine with DNA, RNA, and proteins both in the nucleus and the cytoplasm. However, detailed insights into their biological and mechanistic functions are only beginning to emerge. In this review, we will mainly talk about diverse ways of action of lncRNAs in different sub-cellular locations and provide clues for following studies.