Dicer

• OMIM: 606 241
• UniProt: Q9UPY3

Dicer [ daɪsɚ ] (literally as " dicer " from engl. Dice to " dice " ) is an endoribonuclease that double-stranded RNA into short double-stranded fragments. Depending on the substrate, these products are referred to differently. These fragments are about 20 to 25 nucleotides in length and play the central role in the mechanism of RNA interference. Mutations in the DICER1 gene are associated with early childhood tumors ( pleuropulmonales blastoma ) and mehrknotiger goiter.

Dicer is an RNase III- like enzyme. It contains two RNase III domains and one PAZ domain. The distance between these two domains is determined by a helical portion, the length of which determines the length of the resulting siRNAs. Dicer catalyzes the first step of RNA interference, and initiates formation of the RNA-induced silencing complex (RISC ), whose endonuclease " Argonaut " is able to reduce the mRNA is complementary to the sequence of the resulting siRNA.

Using knockout mosses could be shown that DCL1b, one of four Dicer proteins of Physcomitrella, not for miRNA biogenesis, but for the cutting of the target transcripts is necessary. This led to the elucidation of a novel mechanism of gene regulation.

The name of Dicer was given by Emily Bernstein, a PhD student in the group of Greg Hannon at Cold Spring Harbor Laboratory, which was able to show the first ribonuclease activity of the Dicers to dsRNA.