TARBP2 explained

RISC-loading complex subunit TARBP2 is a protein that in humans is encoded by the TARBP2 gene.^{[1] [2]}

Function

HIV-1, the causative agent of acquired immunodeficiency syndrome (AIDS), contains an RNA genome that produces a chromosomally integrated DNA during the replicative cycle. Activation of HIV-1 gene expression by the transactivator Tat is dependent on an RNA regulatory element (TAR) located downstream of the transcription initiation site. The protein encoded by this gene binds between the bulge and the loop of the HIV-1 TAR RNA regulatory element and activates HIV-1 gene expression in synergy with the viral Tat protein. Alternative splicing results in multiple transcript variants encoding different isoforms. This gene also has a pseudogene.

Interactions

TARBP2 has been shown to interact with Protein kinase R^{[3] [4]} and RBM14.^[5]

Further reading

• Cosentino GP, Venkatesan S, Serluca FC, Green SR, Mathews MB, Sonenberg N . Double-stranded-RNA-dependent protein kinase and TAR RNA-binding protein form homo- and heterodimers in vivo . Proceedings of the National Academy of Sciences of the United States of America . 92 . 21 . 9445–9 . Oct 1995 . 7568151 . 40818 . 10.1073/pnas.92.21.9445 . 1995PNAS...92.9445C . free .
• Kozak CA, Gatignol A, Graham K, Jeang KT, McBride OW . 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) . Genomics . 25 . 1 . 66–72 . Jan 1995 . 7774957 . 10.1016/0888-7543(95)80110-8 .
• Gatignol A, Buckler C, Jeang KT . 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 . Molecular and Cellular Biology . 13 . 4 . 2193–202 . Apr 1993 . 8455607 . 359540 . 10.1128/mcb.13.4.2193.
• Gatignol A, Duarte M, Daviet L, Chang YN, Jeang KT . Sequential steps in Tat trans-activation of HIV-1 mediated through cellular DNA, RNA, and protein binding factors . Gene Expression . 5 . 4–5 . 217–28 . 1996 . 8723388 . 6138028 .
• Kasof GM, Goyal L, White E . Btf, a novel death-promoting transcriptional repressor that interacts with Bcl-2-related proteins . Molecular and Cellular Biology . 19 . 6 . 4390–404 . Jun 1999 . 10330179 . 104398 . 10.1128/mcb.19.6.4390.
• Daviet L, Erard M, Dorin D, Duarte M, Vaquero C, Gatignol A . Analysis of a binding difference between the two dsRNA-binding domains in TRBP reveals the modular function of a KR-helix motif . European Journal of Biochemistry . 267 . 8 . 2419–31 . Apr 2000 . 10759868 . 10.1046/j.1432-1327.2000.01256.x .
• Duarte M, Graham K, Daher A, Battisti PL, Bannwarth S, Segeral E, Jeang KT, Gatignol A . Characterization of TRBP1 and TRBP2. Stable stem-loop structure at the 5' end of TRBP2 mRNA resembles HIV-1 TAR and is not found in its processed pseudogene . Journal of Biomedical Science . 7 . 6 . 494–506 . 2001 . 11060498 . 10.1007/bf02253365 .
• Siffroi JP, Pawlak A, Alfonsi MF, Troalen F, Guellaen G, Dadoune JP . Expression of the TAR RNA binding protein in human testis . Molecular Human Reproduction . 7 . 3 . 219–25 . Mar 2001 . 11228241 . 10.1093/molehr/7.3.219 . free .
• Daher A, Longuet M, Dorin D, Bois F, Segeral E, Bannwarth S, Battisti PL, Purcell DF, Benarous R, Vaquero C, Meurs EF, Gatignol A . 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 . The Journal of Biological Chemistry . 276 . 36 . 33899–905 . Sep 2001 . 11438532 . 10.1074/jbc.M103584200 . free .
• Iwasaki T, Chin WW, Ko L . Identification and characterization of RRM-containing coactivator activator (CoAA) as TRBP-interacting protein, and its splice variant as a coactivator modulator (CoAM) . The Journal of Biological Chemistry . 276 . 36 . 33375–83 . Sep 2001 . 11443112 . 10.1074/jbc.M101517200 . free .
• Bannwarth S, Talakoub L, Letourneur F, Duarte M, Purcell DF, Hiscott J, Gatignol A . Organization of the human tarbp2 gene reveals two promoters that are repressed in an astrocytic cell line . The Journal of Biological Chemistry . 276 . 52 . 48803–13 . Dec 2001 . 11641396 . 10.1074/jbc.M104645200 . free .
• Xu YC, Wu RF, Gu Y, Yang YS, Yang MC, Nwariaku FE, Terada LS . Involvement of TRAF4 in oxidative activation of c-Jun N-terminal kinase . The Journal of Biological Chemistry . 277 . 31 . 28051–7 . Aug 2002 . 12023963 . 10.1074/jbc.M202665200 . free .
• Battisti PL, Daher A, Bannwarth S, Voortman J, Peden KW, Hiscott J, Mouland AJ, Benarous R, Gatignol A . Additive activity between the trans-activation response RNA-binding protein, TRBP2, and cyclin T1 on HIV type 1 expression and viral production in murine cells . AIDS Research and Human Retroviruses . 19 . 9 . 767–78 . Sep 2003 . 14585207 . 10.1089/088922203769232566 .
• Lee JY, Kim H, Ryu CH, Kim JY, Choi BH, Lim Y, Huh PW, Kim YH, Lee KH, Jun TY, Rha HK, Kang JK, Choi CR . Merlin, a tumor suppressor, interacts with transactivation-responsive RNA-binding protein and inhibits its oncogenic activity . The Journal of Biological Chemistry . 279 . 29 . 30265–73 . Jul 2004 . 15123692 . 10.1074/jbc.M312083200 . free .
• Haase AD, Jaskiewicz L, Zhang H, Lainé S, Sack R, Gatignol A, Filipowicz W . TRBP, a regulator of cellular PKR and HIV-1 virus expression, interacts with Dicer and functions in RNA silencing . EMBO Reports . 6 . 10 . 961–7 . Oct 2005 . 16142218 . 1369185 . 10.1038/sj.embor.7400509 .
• Rual JF, Venkatesan K, Hao T, Hirozane-Kishikawa T, Dricot A, Li N, Berriz GF, Gibbons FD, Dreze M, Ayivi-Guedehoussou N, Klitgord N, Simon C, Boxem M, Milstein S, Rosenberg J, Goldberg DS, Zhang LV, Wong SL, Franklin G, Li S, Albala JS, Lim J, Fraughton C, Llamosas E, Cevik S, Bex C, Lamesch P, Sikorski RS, Vandenhaute J, Zoghbi HY, Smolyar A, Bosak S, Sequerra R, Doucette-Stamm L, Cusick ME, Hill DE, Roth FP, Vidal M . Towards a proteome-scale map of the human protein-protein interaction network . Nature . 437 . 7062 . 1173–8 . Oct 2005 . 16189514 . 10.1038/nature04209 . 2005Natur.437.1173R . 4427026 .
• Bannwarth S, Lainé S, Daher A, Grandvaux N, Clerzius G, Leblanc AC, Hiscott J, Gatignol A . Cell-specific regulation of TRBP1 promoter by NF-Y transcription factor in lymphocytes and astrocytes . Journal of Molecular Biology . 355 . 5 . 898–910 . Feb 2006 . 16343534 . 10.1016/j.jmb.2005.11.026 .
• Christensen HS, Daher A, Soye KJ, Frankel LB, Alexander MR, Lainé S, Bannwarth S, Ong CL, Chung SW, Campbell SM, Purcell DF, Gatignol A . Small interfering RNAs against the TAR RNA binding protein, TRBP, a Dicer cofactor, inhibit human immunodeficiency virus type 1 long terminal repeat expression and viral production . Journal of Virology . 81 . 10 . 5121–31 . May 2007 . 17360756 . 1900231 . 10.1128/JVI.01511-06 .

Notes and References

1. Gatignol A, Buckler-White A, Berkhout B, Jeang KT . Characterization of a human TAR RNA-binding protein that activates the HIV-1 LTR . Science . 251 . 5001 . 1597–600 . Mar 1991 . 2011739 . 10.1126/science.2011739 . 1991Sci...251.1597G .
2. Web site: Entrez Gene: TARBP2 Tar (HIV-1) RNA binding protein 2.
3. Cosentino GP, Venkatesan S, Serluca FC, Green SR, Mathews MB, Sonenberg N . Double-stranded-RNA-dependent protein kinase and TAR RNA-binding protein form homo- and heterodimers in vivo . Proceedings of the National Academy of Sciences of the United States of America . 92 . 21 . 9445–9 . Oct 1995 . 7568151 . 40818 . 10.1073/pnas.92.21.9445 . 1995PNAS...92.9445C . free .
4. Daher A, Longuet M, Dorin D, Bois F, Segeral E, Bannwarth S, Battisti PL, Purcell DF, Benarous R, Vaquero C, Meurs EF, Gatignol A . 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 . The Journal of Biological Chemistry . 276 . 36 . 33899–905 . Sep 2001 . 11438532 . 10.1074/jbc.M103584200 . free .
5. Iwasaki T, Chin WW, Ko L . Identification and characterization of RRM-containing coactivator activator (CoAA) as TRBP-interacting protein, and its splice variant as a coactivator modulator (CoAM) . The Journal of Biological Chemistry . 276 . 36 . 33375–83 . Sep 2001 . 11443112 . 10.1074/jbc.M101517200 . free .