TRBP (transactivation response RNA binding protein) is a protein that increases HIV-1 expression and replication by inhibition of the interferon-induced protein kinase PKR. TRBP overexpression is associated with reduced abundance of phosphorylated PKR and stimulation of protein translation. TRBP has a physiological role in spermatogenesis and growth control during development. It is oncogenic upon overexpression, likely because of its association with PKR, with the PKR activator PACT, and with the tumor suppressor Merlin. TRBP was identified as a merlin interacting protein by Gal4-based yeast two-hybrid screening of a human adult brain cDNA library. Merlin can inhibit tumorigenesis mediated by TRBP and can regulate the protein translation pathways controlled by TRBP. Dicer is a key enzyme involved in RNA interference (RNAi) and μRNA (miRNA) pathways. Ago-2, a member of the Argonaute family, Dicer and TRBP comprise the catalytic core of the RNA induced silencing complex (RISC). Required for formation of the RNA induced silencing complex (RISC). Component of the RISC loading complex (RLC), also known as the μ-RNA (miRNA) loading complex (miRLC), which is composed of DICER1, EIF2C2/AGO2 and TARBP2. Within the RLC/miRLC, DICER1 and TARBP2 are required to process precursor miRNAs (pre-miRNAs) to mature miRNAs and then load them onto EIF2C2/AGO2. EIF2C2/AGO2 bound to the mature miRNA constitutes the minimal RISC and may subsequently dissociate from DICER1 and TARBP2. May also play a role in the production of short interfering RNAs (siRNAs) from double-stranded RNA (dsRNA) by DICER1. Binds to the HIV-1 TAR RNA which is located in the long terminal repeat (LTR) of HIV-1, and stimulates translation of TAR-containing RNAs. This is achieved in part at least by binding to and inhibiting EIF2AK2/PKR, thereby reducing phosphorylation and inhibition of EIF2S1/eIF-2-α. May also promote translation of TAR-containing RNAs independently of EIF2AK2/PKR.