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RISC-loading complex subunit TARBP2

Known also as: TAR RNA-binding protein 2, Trans-activation-responsive RNA-binding protein

Known abbreviations: TRBP, TARBP2


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, 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-alpha. May also promote translation of TAR-containing RNAs independently of EIF2AK2/PKR.

Subunit structure

Self-associates. Component of the RISC loading complex (RLC), or micro-RNA (miRNA) loading complex (miRLC), which is composed of DICER1, EIF2C2/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, EIF6, MOV10 and PRKRA. Associates with the 60S ribosome

Subcellular location


Cytoplasm › perinuclear region. Nucleus

Activities in which RISC-loading complex subunit TARBP2 is involved: Pathways in which RISC-loading complex subunit TARBP2 is involved:

NCBI GI number(s): -
Species: Homo sapiens

Links to other databases:

Database ID Link
Uniprot Q15633 Q15633
KEGG hsa:6895 hsa:6895
PFAM: PF00035
InterPro: IPR001159
CATH: - -
SCOP: - -
Solved crystal structures: 2CPN
[PDB] [details]
[PDB] [details]
[PDB] [details]

Protein sequence:

RISC-loading complex subunit TARBP2 (Homo sapiens) is product of expression of TARBP2 gene.


Title Authors Journal Publication date (Issue) PubMed ID
The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC). Gerhard DS, Wagner L, Feingold EA, Shenmen CM, Grouse LH, Schuler G, Klein SL, Old S, Rasooly R, Good P, Guyer M, Peck AM, Derge JG, Lipman D, Collins FS, Jang W, Sherry S, Feolo M, Misquitta L, Lee E, Rotmistrovsky K, Greenhut SF, Schaefer CF, Buetow K, Bonner TI, Haussler D, Kent J, Kiekhaus M, Furey T, Brent M, Prange C, Schreiber K, Shapiro N, Bhat NK, Hopkins RF, Hsie F, Driscoll T, Soares MB, Casavant TL, Scheetz TE, Brown-stein MJ, Usdin TB, Toshiyuki S, Carninci P, Piao Y, Dudekula DB, K Genome Res 2004-10-01 (14) 15489334
TRBP recruits the Dicer complex to Ago2 for microRNA processing and gene silencing. Chendrimada TP, Gregory RI, Kumaraswamy E, Norman J, Cooch N, Nishikura K, Shiekhattar R Nature 2005-08-04 (436) 15973356
Initial characterization of the human central proteome. Burkard TR, Planyavsky M, Kaupe I, Breitwieser FP, Burckstummer T, Bennett KL, Superti-Furga G, Colinge J BMC Syst Biol 2011-01-01 (5) 21269460
A quantitative atlas of mitotic phosphorylation. Dephoure N, Zhou C, Villen J, Beausoleil SA, Bakalarski CE, Elledge SJ, Gygi SP Proc Natl Acad Sci U S A 2008-08-05 (105) 18669648
Human RISC couples microRNA biogenesis and posttranscriptional gene silencing. Gregory RI, Chendrimada TP, Cooch N, Shiekhattar R Cell 2005-11-18 (123) 16271387
TRBP, a regulator of cellular PKR and HIV-1 virus expression, interacts with Dicer and functions in RNA silencing. Haase AD, Jaskiewicz L, Zhang H, Laine S, Sack R, Gatignol A, Filipowicz W EMBO Rep 2005-10-01 (6) 16142218
A human, ATP-independent, RISC assembly machine fueled by pre-miRNA. Maniataki E, Mourelatos Z Genes Dev 2005-12-15 (19) 16357216
The role of PACT in the RNA silencing pathway. Lee Y, Hur I, Park SY, Kim YK, Suh MR, Kim VN EMBO J 2006-01-08 (25) 16424907
Human TRBP and PACT directly interact with each other and associate with dicer to facilitate the production of small interfering RNA. Kok KH, Ng MH, Ching YP, Jin DY J Biol Chem 2007-06-15 (282) 17452327
RNA helicase A interacts with RISC in human cells and functions in RISC loading. Robb GB, Rana TM Mol Cell 2007-05-25 (26) 17531811
MicroRNA silencing through RISC recruitment of eIF6. Chendrimada TP, Finn KJ, Ji X, Baillat D, Gregory RI, Liebhaber SA, Pasquinelli AE, Shiekhattar R Nature 2007-06-14 (447) 17507929
In vitro reconstitution of the human RISC-loading complex. MacRae IJ, Ma E, Zhou M, Robinson CV, Doudna JA Proc Natl Acad Sci U S A 2008-02-15 (105) 18178619
A TARBP2 mutation in human cancer impairs microRNA processing and DICER1 function. Melo SA, Ropero S, Moutinho C, Aaltonen LA, Yamamoto H, Calin GA, Rossi S, Fernandez AF, Carneiro F, Oliveira C, Ferreira B, Liu CG, Villanueva A, Capella G, Schwartz S Jr, Shiekhattar R, Esteller M Nat Genet 2009-03-01 (41) 19219043
Organization of the human tarbp2 gene reveals two promoters that are repressed in an astrocytic cell line. Bannwarth S, Talakoub L, Letourneur F, Duarte M, Purcell DF, Hiscott J, Gatignol A... J Biol Chem 2001-12-28 (276) 11641396
Characterization of a human TAR RNA-binding protein that activates the HIV-1 LTR. Gatignol A, Buckler-White A, Berkhout B, Jeang KT... Science 1991-03-01 (251) 2011739
Genetic mapping in human and mouse of the locus encoding TRBP, a protein that binds the TAR region of the human immunodeficiency virus (HIV-1). Kozak CA, Gatignol A, Graham K, Jeang KT, McBride OW... Genomics 1995-02-01 (25) 7774957
Relatedness of an RNA-binding motif in human immunodeficiency virus type 1 TAR RNA-binding protein TRBP to human P1/dsI kinase and Drosophila staufen. Gatignol A, Buckler C, Jeang KT... Mol Cell Biol 1993-04-01 (13) 8455607
Two dimerization domains in the trans-activation response RNA-binding protein (TRBP) individually reverse the protein kinase R inhibition of HIV-1 long terminal repeat expression. Daher A, Longuet M, Dorin D, Bois F, Segeral E, Bannwarth S, Battisti PL, Purcell DF, Benarous R, Vaquero C, Meurs EF, Gatignol A... J Biol Chem 2001-09-07 (276) 11438532
The TAR RNA-binding protein, TRBP, stimulates the expression of TAR-containing RNAs in vitro and in vivo independently of its ability to inhibit the dsRNA-dependent kinase PKR. Dorin D, Bonnet MC, Bannwarth S, Gatignol A, Meurs EF, Vaquero C... J Biol Chem 2003-01-14 (278) 12475984
Interactions between the double-stranded RNA-binding proteins TRBP and PACT define the Medipal domain that mediates protein-protein interactions. Laraki G, Clerzius G, Daher A, Melendez-Pena C, Daniels S, Gatignol A... RNA Biol 2008-04-01 (5) 18421256

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Last modification of this entry: April 26, 2013.

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