Fig. 3From: Autophagy in cancers including brain tumors: role of MicroRNAsMicroRNA processing and function. In order to produce hairpin-structured pre-miRNAs, a core ribonuclease complex, such as Drosha or the respective modulatory sub-unit DGCR8 is used to process them in the nucleus. Following cleavage, these hairpin-structured premiRNAs are transferred from the nucleus into the cytoplasm. Moreover, further cleavage of the pre-miRNA hairpin structure in the cytoplasm is carried out by DICER protein, resulting in the formation of long miRNA duplexes. These duplexes are loaded into the RNA-induced silencing complex (RISC). In addition, Argonaute (AGO) proteins are essential elements of the RISC that direct mature single-stranded miRNAs to their target mRNAs. However, the destiny of the targeted mRNA is governed by the interrelationship between the miRNA response elements (MRE) and the mature miRNA seed sequences. Therefore, base-pairing of the target mRNA to the guide miRNA leads to its endonuclease-mediated cleavage in a slicer-dependent mannerBack to article page