Identification of human microRNA targets from isolated argonaute protein complexes.

MicroRNAs (miRNAs) constitute a class of small non-coding RNAs that regulate gene expression on the level of translation and/or mRNA stability. Mammalian miRNAs associate with members of the Argonaute (Ago) protein family and bind to partially complementary sequences in the 3' untranslated region (UTR) of specific target mRNAs. Computer algorithms based on factors such as free binding energy or sequence conservation have been used to predict miRNA target mRNAs.

Argonaute proteins: mediators of RNA silencing.

Small regulatory RNAs such as short interfering RNAs (siRNAs), microRNAs (miRNAs), and Piwi interacting RNAs (piRNAs) have been discovered in the past, and it is becoming more and more apparent that these small molecules have key regulatory functions. Small RNAs are found in all higher eukaryotes and play important roles in cellular processes as diverse as development, stress response, or transposon silencing. Soon after the discovery of small regulatory RNAs, members of the Argonaute protein family were identified as their major cellular protein interactors.

Identification of novel argonaute-associated proteins.

RNA silencing processes are guided by small RNAs known as siRNAs and microRNAs (miRNAs) . They reside in ribonucleoprotein complexes, which guide the cleavage of complementary mRNAs or affect stability and translation of partial complementary mRNAs . Argonaute (Ago) proteins are at the heart of silencing effector complexes and bind the single-stranded siRNA and miRNA .

Chemical inhibitors when timing is critical: a pharmacological concept for the maturation of T cell contacts.

Cellular signal transduction proceeds through a complex network of molecular interactions and enzymatic activities. The timing of these molecular events is critical for the propagation of a signal and the generation of a specific cellular response. To define the timing of signalling events, we introduce the combination of high-resolution confocal microscopy with the application of small-molecule inhibitors at various stages of signal transduction in T cells.