Required for formation of the RNA induced silencing complex (RISC). Component of the RISC loading complex (RLC), also known as the micro-RNA (miRNA) loading complex (miRLC), which is composed of DICER1, 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 AGO2. 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. (Microbial infection) 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 (PubMed:2011739, PubMed:11438532, PubMed:12475984). This is achieved in part at least by binding to and inhibiting EIF2AK2/PKR, thereby reducing phosphorylation and inhibition of EIF2S1/eIF-2-alpha (PubMed:11438532). May also promote translation of TAR-containing RNAs independently of EIF2AK2/PKR (PubMed:12475984). Mediates recruitment of FTSJ3 methyltransferase to HIV-1 RNA, leading to 2'-O-methylation of the viral genome, allowing HIV-1 to escape the innate immune system (PubMed:30626973). Self-associates. Component of the RISC loading complex (RLC), or micro-RNA (miRNA) loading complex (miRLC), which is composed of DICER1, AGO2 and TARBP2. Note that the trimeric RLC/miRLC is also referred to as RISC. Interacts with EIF2AK2/PKR and inhibits its protein kinase activity. Interacts with DHX9 and PRKRA. Interacts with DICER1, AGO2, MOV10, EIF6 and RPL7A (60S ribosome subunit); they form a large RNA-induced silencing complex (RISC) (PubMed:17507929). (Microbial infection) Interacts with FTSJ3; forms a complex with FTSJ3 and HIV-1 TAR RNA. (Microbial infection) Interacts with ebolavirus VP30; this interaction, which occurs only in the presence of siRNA, prevents TARBP2 binding to DICER1 and thus allows the virus to counteract host RNA silencing. (Microbial infection) Interacts with ebolavirus VP35; this interaction prevents TARBP2 binding to DICER1 and thus allows the virus to counteract host RNA silencing. Belongs to the TARBP2 family. A paper describing truncating mutations of TARBP2 in tumor cells and resultant effects on DICER1 stability and miRNA processing has been retracted, due to concerns of image duplication in some of the figures.