U1 Adaptors are a nanotechnology used for gene silencing - the prevention of protein production by a particular gene of interest. Unlike antisense and RNA interference gene silencers, U1 adaptors work at the spliceosome: macromolecular assemblies inside the cell nucleus that process pre-mRNA transcripts prior to export into the cytoplasm and translation into proteins. Specifically, a U1 adaptor (orange-red) can be tailor-made to bind pre-mRNA (blue) from a specific gene and tether it firmly to the U1 snRNP component of the spliceosome, thereby gumming up the works. This action prevents the addition of a poly(A)-tail to the pre-mRNA, which leads to rapid degradation by RNase enzymes and prevents its use in protein synthesis.