TARBP2
TARBP2 (RISC-loading complex subunit TARBP2, also known as Trbp) is a human RNA-binding protein first identified through its binding to the HIV-1 TAR RNA element. It is a member of the TARBP2 family and belongs to the HGNC group of RISC loading complex subunits. Browse Assay Genie's current range of TARBP2 research reagents below, or read on for the biology behind the target.
The best-characterised function of TARBP2 in the source annotation relates to HIV-1 infection. The protein binds the TAR RNA element, which lies in the long terminal repeat of the virus, and stimulates translation of TAR-containing RNAs. In part, this occurs by binding to and inhibiting EIF2AK2 (PKR), which reduces phosphorylation and inhibition of EIF2S1 (eIF-2-alpha). TARBP2 may also promote translation of TAR-containing RNAs independently of EIF2AK2.
TARBP2 also mediates recruitment of the methyltransferase FTSJ3 to HIV-1 RNA. This leads to 2'-O-methylation of the viral genome, which allows HIV-1 to escape the innate immune system. NCBI Gene describes the TARBP2 protein as binding between the bulge and the loop of the TAR regulatory element and activating HIV-1 gene expression in synergy with the viral Tat protein, which depends on TAR for transactivation.
The human TARBP2 gene encodes a protein found in the cytoplasm, including the perinuclear region, and in the nucleus. Alternative splicing produces multiple transcript variants encoding different isoforms, and the gene also has a pseudogene. Previous names include TAR (HIV-1) RNA binding protein 2 and TARBP2, RISC loading complex RNA binding subunit; the current HGNC name reflects its place among RISC loading complex subunits. Orthologous genes are named Tarbp2 in mouse and rat, which allows comparative work on the TARBP2 gene and protein in rodent models.
TARBP2 binds the viral TAR element and acts with Tat to activate HIV-1 gene expression, making it a focus for studies of viral transcript regulation.
By inhibiting EIF2AK2/PKR and limiting eIF-2-alpha phosphorylation, TARBP2 stimulates translation of TAR-containing RNAs, a mechanism studied in RNA-binding protein research.
TARBP2 recruits FTSJ3 to viral RNA for 2'-O-methylation of the HIV-1 genome, which allows the virus to escape the innate immune system.
HGNC classifies TARBP2 as a RISC loading complex subunit, placing it in research on RNA-binding components of this complex.
TARBP2 binds the HIV-1 TAR RNA element and stimulates translation of TAR-containing RNAs, partly by inhibiting EIF2AK2/PKR. It also recruits FTSJ3 methyltransferase to HIV-1 RNA, leading to 2'-O-methylation of the viral genome and helping the virus escape innate immunity.
TARBP2 is also known as Trbp. Earlier names include TAR (HIV-1) RNA binding protein 2 and TARBP2, RISC loading complex RNA binding subunit. The current HGNC name is TARBP2 subunit of RISC loading complex. Alternative splicing gives multiple transcript variants encoding different isoforms.
Yes. Mouse and rat both have an ortholog named Tarbp2. The protein belongs to the TARBP2 family. For work in rodent samples, check the datasheet of any product for its validated reactivity.
Interaction partners of TARBP2, including PKR, eIF-2-alpha and FTSJ3, with related products at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt Q15633; product specifications from Assay Genie datasheets.