A team of researchers at Institute of Biochemistry and Cell Biology (SIBCB), Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, reported on November 5th online in Nucleic Acids Research that a new type of expression vector (snoVector) can stably express virtually any sequence of interest and constrain its accumulation to the nucleus.
Long noncoding RNAs (lncRNAs) are transcribed from thousands of loci of mammalian genomes and have been implicated in many important biological processes. Recent studies have revealed that many regulatory lncRNAs are produced and matured in the nucleus. Very often such RNAs never leave the nucleus to exert their functions. However, commonly used vectors that were designed to express mRNAs have not been optimized for the study of nuclear RNAs, leading to frequently cytoplasmic localization of nuclear RNAs when expressed from such vectors. Thus, new vectors are needed to develop to express lncRNAs in the correct cellular compartment.
Under the supervision of Prof. CHEN Lingling from SIBCB, YIN Qingfei, HU Shibin and their colleagues have demonstrated that some common expression vectors (such as pEGFP-C1 and pcDNA3.0) designed for mRNA expression are inappropriate for the expression of nuclear RNAs. To overcome this problem, they have developed “snoVectors” that can stably express virtually any sequence of interest and constrain its accumulation to the nucleus (Figure 1). Such sequences include lncRNAs, mRNAs, intronic sequences and pre-miRNAs. Importantly, they have further shown that RNAs, such as mNEAT1 lncRNA, expressed from snoVectors can retain normal nuclear associations and functions. Thus, the newly developed snoVectors should be very useful in conditions where nuclear RNA function is studied or where export to the cytoplasm needs to be avoided.
This study, entitled “SnoVectors for nuclear expression of RNA” was done in collaboration with Prof. YANG Li at CAS-MPG Partner Institute for Computational Biology and with Prof. Gordon Carmichael at University of Connecticut Health Center. This study was supported by grants from Chinese Academy of Sciences, the Ministry of Science and Technology of China, the National Natural Science Foundation of China and Shanghai Institutes for Biological Sciences.
Top, a schematic illustration of the design of snoVector and the processing of snoRNA-ended-RNAs expressed from snoVectors. Bottom, RNAs expressed from the snoVector are absolutely retained in the nucleus, while those from pEGFP-C1 are not. Green, different RNAs expressed from snoVector or from pEGFP-C1 in HeLa cells.
(Images provided by Prof. CHEN Lingling’s group)
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