5'-3' Exoribonuclease 2 (XRN2) also known as Dhm1-like protein is an exoribonucleaseenzyme that in humans is encoded by the XRN2gene.[1]
The human gene encoding XRN2 shares similarity with the mouse Dhm1 and the yeast's Dhp1 (Schizosaccharomyces pombe) or RAT1 (Saccharomyces) genes. The yeast gene is involved in homologous recombination and RNAmetabolism, such as RNA synthesis and RNA trafficking and termination.[2] Complementation studies show that Dhm1 has a similar function in mouse as Dhp1.
Human XRN2 is involved in the torpedo model of transcription termination.[3]
The C. elegans homologue, XRN-2, is involved in the degradation of certain mature miRNAs and their dislodging from miRISC miRNAs.[4]
In yeast, the Rat1 protein has been shown to also be involved in the torpedo transcription termination model. When a polyadenylation site has been detected on the nascent RNA and cleaved by the RNA polymerase II, the Rtt103 factor recruits Rat1 and attaches it to free end. The exonuclease activity of Rat1 degrades the RNA strand and halts transcriptions upon catching up to the polymerase.[2]
References
↑Zhang M, Yu L, Xin Y, Hu P, Fu Q, Yu C, Zhao S (July 1999). "Cloning and mapping of the XRN2 gene to human chromosome 20p11.1-p11.2". Genomics. 59 (2): 252–4. doi:10.1006/geno.1999.5866. PMID10409438.
Deloukas P, Matthews LH, Ashurst J, et al. (2001). "The DNA sequence and comparative analysis of human chromosome 20". Nature. 414 (6866): 865–71. doi:10.1038/414865a. PMID11780052.
Beausoleil SA, Villén J, Gerber SA, et al. (2006). "A probability-based approach for high-throughput protein phosphorylation analysis and site localization". Nat. Biotechnol. 24 (10): 1285–92. doi:10.1038/nbt1240. PMID16964243.
Lu Y, Liu P, James M, et al. (2010). "Genetic variants cis-regulating Xrn2 expression contribute to the risk of spontaneous lung tumor". Oncogene. 29 (7): 1041–9. doi:10.1038/onc.2009.396. PMID19915612.
Lejeune F, Li X, Maquat LE (2003). "Nonsense-mediated mRNA decay in mammalian cells involves decapping, deadenylating, and exonucleolytic activities". Mol. Cell. 12 (3): 675–87. doi:10.1016/S1097-2765(03)00349-6. PMID14527413.
Ota T, Suzuki Y, Nishikawa T, et al. (2004). "Complete sequencing and characterization of 21,243 full-length human cDNAs". Nat. Genet. 36 (1): 40–5. doi:10.1038/ng1285. PMID14702039.
Li J, Zheng H, Ji C, et al. (2005). "A novel splice variant of human XRN2 gene is mainly expressed in blood leukocyte". DNA Seq. 16 (2): 143–6. doi:10.1080/10425170500066771. PMID16147866.