MicroRNAs (miRNAs) are small endogenous non-coding functional RNAs. They can play vital roles in post-transcriptional regulating mRNAs transcripts in nearly all biological processes. More and more reports on miRNAs come from different species (animal, plant, bacteria, virus) in the researches in development, immunity, apoptosis, tumor, virus-host interaction. These recent findings provide new i...

miRNAs are important regulatory elements for gene expression that are involved in diverse physiologic and pathologic processes. Canonical miRNA biogenesis consists of a two-step processing, from primary transcripts (pri-miRNA) to precursor miRNAs (pre-miRNA) mediated by Drosha in the nucleus and from pre-miRNAs to mature miRNAs mediated by Dicer in the cytoplasm. Various routes of miRNA maturat...

MicroRNAs (miRNAs) are endogenously expressed small non-coding RNAs acting at the post-transcriptional level where they promote mRNA degradation and block protein translation. Recent findings suggest that complex transcriptional and post-transcriptional circuits control miRNAs. STAT3 has emerged as an important regulator of their expression and biogenesis and, in turn, STAT3 signaling pathways ...

Introns represent almost half of the human genome, although they are eliminated from transcripts through RNA splicing. Yet, different classes of non-canonical miRNAs have been proposed to originate directly from intron splicing. Here, we considered the alternative splicing of introns as an interesting source of miRNAs, compatible with a developmental switch. We report computational prediction o...

In Arabidopsis thaliana, four different dicer-like (DCL) proteins have distinct but partially overlapping functions in the biogenesis of microRNAs (miRNAs) and siRNAs from longer, noncoding precursor RNAs. To analyze the impact of different components of the small RNA biogenesis machinery on the transcriptome, we subjected dcl and other mutants impaired in small RNA biogenesis to whole-genome t...

In plants, the known microRNAs (miRNAs) are produced as approximately 21 nucleotide (nt) duplexes from their precursors by Dicer-like 1 (DCL1). They are incorporated into Argonaute 1 (AGO1) protein to regulate target gene expression primarily through mRNA cleavage. We report here the discovery of a class of miRNAs in the model monocot rice (Oryza sativa). These are 24 nt in length and require a...

microRNAs (miRNAs) are short ~22 nucleotides (nt) ribonucleic acids which post-transcriptionally regulate gene expression. miRNAs are key regulators of all cellular processes, and the correct expression of miRNAs in an organism is crucial for proper development and cellular function. As a result, the miRNA biogenesis pathway is highly regulated. In this review, we outline the basic steps of miR...

Abstract Background MiRNAs play critical roles in the regulation of cellular function, life span, and aging process. They can affect longevity positively negatively through different pathways. Main text are a group short non-coding RNAs that regulate gene expressions at post-transcriptional levels. The types alterations miRNAs biogenesis, mRNA expressions, activities miRNA-protein complexes nor...

MicroRNAs (miRNAs), which function as regulators of gene expression in eukaryotes, are processed from larger transcripts by sequential action of nuclear and cytoplasmic ribonuclease III-like endonucleases. We show that Exportin-5 (Exp5) mediates efficient nuclear export of short miRNA precursors (pre-miRNAs) and that its depletion by RNA interference results in reduced miRNA levels. Exp5 binds ...

MicroRNAs (miRNA) are small RNAs that regulate the translation of thousands of message RNAs and play a profound role in mammalian biology. Over the past 5 years, significant advances have been made towards understanding the pathways that generate miRNAs and the mechanisms by which miRNAs exert their regulatory functions. An emerging theme is that miRNAs are both generated by and utilized by lar...