Mutations in the tumor suppressor TP53 occur in almost all advanced ovarian cancers and in many advanced serous endometrial cancers. Mutations in TP53 can alter the function of the p53 protein, and some mutations result in a mutated protein with oncogenic activity. Previously referred to as gain of function (GOF) p53 proteins, we now term these "oncomorphic" mutations to better describe their f...

RNA interference (RNAi) based approaches can potentially be used to control insect pests. These approaches may depend on the usage of microRNA (miRNA) or double stranded RNA (dsRNA) mediated gene knockdown, which likely involves proteins that regulate these pathways, such as Argonaute 1 (Ago1), Argonaute 2 (Ago2), Dicer 1 (Dcr1), Dicer 2 (Dcr2), and Drosha in insects. We previously performed fu...

DiGeorge critical region 8 (DGCR8) is essential for maturation of microRNAs (miRNAs) in animals. In the cleavage of primary transcripts of miRNAs (pri-miRNAs) by the Drosha nuclease, the DGCR8 protein directly binds and recognizes pri-miRNAs through a mechanism currently controversial. Our previous data suggest that DGCR8 trimerizes upon cooperative binding to pri-mir-30a. However, a separate s...

MicroRNAs (miRNAs) are tiny regulators of gene expression that are processed from longer primary transcripts. In this issue, Han et al. (2006) report some of the structural features of the primary transcript that ensure that the Drosha-DGCR8 enzyme complex liberates precisely the correct precursor sequence, enabling production of a fully functional miRNA.

Structural and biochemical studies have begun to elucidate the pathway of RNA silencing that leads to the formation of the RISC complex. The outstanding feature of this pathway is the precise recognition and processing of double-stranded RNA. We present a review of recent structures that illustrate the molecular mechanisms contributing to these two related functions, highlighting models of Dros...