ABSTRACT
Objective To screen and identify mRNAs targeted by human cytomegalovirus-encoded miR-US33-1-5p (HCMV miR-US33-1-5p) for understanding the biological functions of HCMV miR-US33-1-5p. Methods Potential target mRNAs of HCMV miR-US33-1-5p were screened out by using hybrid-PCR, a simple and effective method. Dual-Luciferase Reporter Assay System was used to identify the binding abili-ties of HCMV miR-US33-1-5p to 3′-UTRs of these potential target mRNAs. Results Twelve potential mRNAs targeted by HCMV miR-US33-1-5p were screened out in human embryo lung fibroblast cells infected with HCMV. Luciferase activities of 3′-UTRs of seven target mRNAs were significantly down-regulated. Conclusion Proteins encoded by these target mRNAs are involved in virus replication,immune system reg-ulation,protein synthesis,cell cycle regulation,energy metabolism and so on. Identification of mRNAs tar-geted by HCMV miR-US33-1-5p is helpful for further studies on biological functions of miR-US33-1-5p.
ABSTRACT
MicroRNAs (miRNAs) act by binding to complementary sites on target messenger RNA (mRNA) to induce mRNA degradation and/or translational repression. To investigate the influence of miRNAs at transcript levels, two human miRNAs (miR-1 and miR-124) were transfected into HeLa cells and microarrays used to examine changes in the mRNA profile showed that many genes were downregulated and that the fold decreases in levels of these target mRNAs differed remarkably. Features depicting interactions between miRNAs and their respective target mRNAs, such as the number of putative binding sites, the strength of complementary matches and the degree of stabilization of the binding duplex, were extracted and analyzed. It was found that, for a given target mRNA, both the quality and quantity of miRNA binding sites significantly affected its degree of destabilization. To delineate these types of interactions, a simple statistical model was proposed, which considers the combined effects of both the quality and quantity of miRNA binding sites on the degradation levels of target mRNAs. The analysis provides insights into how any animal miRNA might interact with its target mRNA. It will help us in designing more accurate methods for predicting miRNA targets and should improve understanding of the origins of miRNAs.
ABSTRACT
MicroRNAs(miRNAs) act by binding to complementary sites on target messenger RNA(mRNA) to induce mRNA degradation and/or translational repression.To investigate the influence of miRNAs at transcript levels,two human miRNAs(miR-1 and miR-124) were transfected into HeLa cells and microarrays used to examine changes in the mRNA profile showed that many genes were downregulated and that the fold decreases in levels of these target mRNAs differed remarkably.Features depicting interactions between miRNAs and their respective target mRNAs,such as the number of putative binding sites,the strength of complementary matches and the degree of stabilization of the binding duplex,were extracted and analyzed.It was found that,for a given target mRNA,both the quality and quantity of miRNA binding sites significantly affected its degree of destabilization.To delineate these types of interactions,a simple statistical model was proposed,which considers the combined effects of both the quality and quantity of miRNA binding sites on the degradation levels of target mRNAs.The analysis provides insights into how any animal miRNA might interact with its target mRNA.It will help us in designing more accurate methods for predicting miRNA targets and should improve understanding of the origins of miRNAs.
ABSTRACT
microRNAs (miRNAs) are a recently discovered family of small non-coding RNAs, which exist in eukaryotes and regulate gene expression post-transcriptionally by binding to complementary sites on target mRNAs. MiRNAs play important roles in regulation of cell proliferation, development, apoptosis and cell differentiation. It’s predicted that about 1% human known genes encode microRNAs and microRNAs may regulate 10～30%of the genes in the human genome. The paper focus on the knowledge about how to recognize miRNAs and identify their target mRNAs.