Long non-coding RNA SLERT plays an important role in cell nucleation function and RNA polymerase I (Pol I) transcription.

On May 5, the international academic journal Cell published the latest research results on long non-coding RNA by Chen Lingling of the Institute of Biochemistry and Cell Biology of the Shanghai Institute of Life Sciences of the Chinese Academy of Sciences: SLERT regulations DDX21-rings with Pol I transcription, which reveals the important role of long non-coding RNA SLERT in cellular kernel function and RNA polymerase I (Pol I) transcription.
human cells contain about 400 copies of the dna (rDNA) sequence of the nuclear glycosome, distributed on five chromosomes, and these areas containing rDNA sequences are called nucleolar organization regions (NOR).
kernels around NOR and are important sites for RNA polymerase I transcription of RNA (rRNA) and rRNA processing.
rhRNA transcription disorders are closely related to disease.
rRNA transcription means that the RNA is dysgenes, which can lead to bone marrow failure anemia, while excessive rRNA transcription is prone to multiple cancers.
because rDNA sequences are highly repetitive, it is still unknown how differences in rDNA expressions on these sequences are implemented and related Pol I transcription regulation mechanisms are available.
classical long non-coding RNA and mRNA structure similar, containing 5' end hat and 3' end poly adenosine tail structure, widely involved in the regulation of various important life activities.
In addition, recently, Chen Lingling's research team and other international researchers have found that there are a series of long non-coding RNA molecular families with special structures in mammalian cells, such as lncRNAs and ring RNA with special structures of small nucleorna (snoRNA), and have important regulatory functions.
the study, using the sequencing and analysis of a full transcriptional group without poly(A) tail RNA created earlier, found a new lncRNA from the sub-region of the human protein-coding gene TBRG4, whose molecular ends contain snoRNA structures and facilitate transcription of ribosome RNA prebodies (pre-rRNA), hence the name SlerT (sno-end RNA lncrna pre-ribos.
study found that SLERT comes from a variable shear of tbrg4 pre-mRNA and is positioned in the nucleus (illustrated).
using CRISPR/CAS9 technology to precisely knock out SLERT, the researchers found that the absence of SLERT led to a decrease in Pol I transcription activity.
further studies have found that SLERT can be combined with RNA anti-spinase DDX21.
researchers made a detailed and detailed look at the positioning of DDX21 in cell nuclei using Structural Illumination Microscopy (SIM), and for the first time found that DDX21 formed a ring structure (illustrated) about 400nm in diameter around the Pol I complex in the cell nuclei;
in-depth studies have shown that the binding of SLERT to DDX21 can alter the protein composition of DDX21, thereby adjusting the rules of the DDX21 ring in the cell nucleus, and ultimately by removing the inhibition of the DDX21 ring on Pol I to play a positive role in regulating PolI transcription.
it's worth noting that the researchers also found that SLERT knockout inhibited in-body tumorization in mice, a finding that also provided a new target for tumor-targeted treatment for pre-rRNA transcription.
this study is the first to find long non-coding RNA in human cells that regulate Pol I transcription, and explains the distinctive function of this RNA, expanding the mechanism of action of long non-coding RNA.
the study analyzed the molecular mechanisms of rDNA, DDX21 ring, RNA polymerase I, SLERT, and pre-rRNA, and revealed that the size of the DDX21 ring is different for Pol I The regulatory mechanism of transcription (illustrated) and the control of SLERT on the DDX21 ring suggest a mechanism for regulating Pol I transcription through the SLERT-DDX21 ring and controlling the difference expression of rDNA.
the new mechanism of Pol I transcription from a new perspective, and also provides a new direction for further study of the structure and function of nuclear kernels.
the work, under the guidance of researcher Chen Lingling, was carried out mainly by Yu Yuhang, Yao Runwen and Zhang Yang, Ph.D. students of the Institute of Bioinsculation and Cells.
the study was also greatly supported by Yang Li, a researcher at the Institute of Computational Biology of the Chinese Academy of Sciences-Map, as well as the Cell Analysis Technology Platform of the Institute of Plant Physiology and Ecology, the Cell Analysis Technology Platform of Biochemistry and Cells, and the Animal Experimental Technology Platform.
funding support comes from the Ministry of Science and Technology, the Fund Committee and the Chinese Academy of Sciences.
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