Search results
Results from the WOW.Com Content Network
miRNA biogenesis in plants differs from animal biogenesis mainly in the steps of nuclear processing and export. Instead of being cleaved by two different enzymes, once inside and once outside the nucleus, both cleavages of the plant miRNA are performed by a Dicer homolog, called Dicer-like1 (DL1). DL1 is expressed only in the nucleus of plant ...
An miRNA that remains constant in its expression through these stages is proposed to have a role in regulating general aspects of cell physiology. [8] Thus it was becoming evident in 2003 shortly after its discovery, that the mir-92 miRNA and associated family members are providing functional roles to the cell cycle and to cell signalling, and ...
The Let-7 microRNA precursor gives rise to let-7, a microRNA (miRNA) involved in control of stem-cell division and differentiation. [1] let-7, short for "lethal-7", was discovered along with the miRNA lin-4 in a study of developmental timing in C. elegans, [2] making these miRNAs the first ever discovered.
A miRNA can be derived from each arm of the pre-miRNA hairpin. Historically, the least common of these two miRNA products was denoted by the addition of * to the miRNA name, however the modern convention is to denote mature miRNA products as 5p or 3p. [11] Both mir-10 and mir-10* have been detected in Drosophila.
Dicer, also known as endoribonuclease Dicer or helicase with RNase motif, is an enzyme that in humans is encoded by the DICER1 gene.Being part of the RNase III family, Dicer cleaves double-stranded RNA (dsRNA) and pre-microRNA (pre-miRNA) into short double-stranded RNA fragments called small interfering RNA and microRNA, respectively.
The RNase III Dicer is a critical member of RISC that initiates the RNA interference process by producing double-stranded siRNA or single-stranded miRNA. Enzymatic cleavage of dsRNA within the cell produces the short siRNA fragments of 21-23 nucleotides in length with a two-nucleotide 3' overhang.
Many mammalian genomes encode four closely related miR-29 precursors that are transcribed in two transcriptional units. For example, human miR-29a and miR-29b-1 are processed from an intron of a long non-coding transcript pri-miRNA (lnc-pri-miRNA) LOC646329 from chromosome 7. miR-29b-2 (identical in sequence to miR-29b-1) and miR-29c are co-transcribed from chromosome 1.
These two proteins homeostatically control miRNA biogenesis by an auto-feedback loop. [16] A 2nt 3' overhang is generated by Drosha in the nucleus recognized by Dicer in the cytoplasm, which couples the upstream and downstream processing events. Pre-miRNA is then further processed by the RNase Dicer into mature miRNAs in the cell cytoplasm.