Why do miRNAs live in the miRNP?

Do tiny RNAs now have a home?

Noncoding RNAs function in diverse pathways—dosage compensation, gene imprinting, transcriptional regulation, pre-mRNA splicing, and the control of mRNA translation—and they carry out these roles from within specific RNA–protein complexes that ensure each noncoding RNA is in the right cellular compartment with the appropriate proteins needed to accomplish its biochemical function. Thus, identifying the ribonucleoprotein complex (RNP) associated with a noncoding RNA gives clues to its cellular function and biochemical mechanism by revealing the proteins whose company it keeps. The discovery by Dreyfuss and coworkers that microRNAs reside in a ∼550-kD (15S) particle provides new clues toward the functions of this novel and surprisingly large class of tiny, noncoding RNAs (Mourelatos et al. 2002).