Disease relevance of REXO1

• By using fresh peripheral blood mononuclear cells, the expression of tax1/rex1 mRNA was detected in five of the six adult T-cell leukemia patients and four of the eight HTLV-I carriers examined [1].
• Furthermore, a p21X protein lacking the N-terminus of Rex1 was expressed at high levels; our data indicate that p21X is translated from the 1.6-kb mRNA which is derived primarily from deleted proviruses [2].

High impact information on REXO1

• The Leishmania major RNA ligase-containing complex protein 2 expressed in insect cells has a 3'-5' exoribonuclease activity and was therefore renamed RNA editing exonuclease 1 (REX1) [3].
• The evidence involves both in vivo down-regulation of REX1 expression in Trypanosoma brucei by RNA interference and the reconstitution of precleaved U-deletion in vitro editing with only two recombinant enzymes: recombinant REX1 and recombinant RNA editing ligase 1 [3].
• The amounts of tax1/rex1 mRNA detected corresponded to approximately 10(5) to 10(6) times less than that in the HTLV-I-infected MT-2 cell line [1].
• REX1, a novel gene required for DNA repair [4].
• At least three of these ancient Rex1 lineages were detected within the genome of poeciliids [5].

Biological context of REXO1

• Evidence is presented that REX1 is responsible for deletion of the 3' overhanging Us from the bridged mRNA 5' cleavage fragment and that RNA editing ligase 1 is responsible for the ligation of the two mRNA cleavage fragments in U-deletion editing [3].
• Different Rex1 elements show a conserved terminal 3' untranslated region followed by oligonucleotide tandem repeats of variable size and sequence [5].
• We have generated a molecular model of the human REX1 zinc finger domains based on the crystal structure of the YY1 transcription factor [6].
• Expression of TH followed down-regulation of genes associated with cell proliferation, OCT-3/4, REX-1, and beta-catenin [7].
• RESULTS: Sequence analysis and homology modeling of the Endonuclease/Exonuclease/Phosphatase (EEP) domain at the C-terminus of REX1 and REX2 highlights a common active site shared by all EEP domains [8].

Anatomical context of REXO1

• Double immunofluorescence labeling in COS7 cells suggested that EloA-BP1 and Elongin A are colocalized to the cell nucleus [9].
• Detection of mRNA for the tax1/rex1 gene of human T-cell leukemia virus type I in fresh peripheral blood mononuclear cells of adult T-cell leukemia patients and viral carriers by using the polymerase chain reaction [1].
• Western analyses confirmed expression of the human REX1 (ZFP42) protein in MDA-MB-468 cells and normal human keratinocytes [6].
• This research has identified model human cell culture systems, in addition to embryonic stem (ES) cells, in which Rex-1 is expressed, and this should enable the characterization of REX1 functions in normal adult epithelial cells and tumorigenic stem cells [6].

Associations of REXO1 with chemical compounds

• We discovered that, at proliferative state, these cells express transcription factors of pluripotent cells, OCT-3/4 and REX-1, and embryonic cell surface antigens SSEA-1, SSEA-3, and SSEA-4, as well as TRA-1-60 and TRA-1-81 [7].

Other interactions of REXO1

• Here, we report on the cloning and characterization of a novel human exonuclease domain-containing protein, Elongin A-binding protein 1 (EloA-BP1) [9].
• In contrast, low pO2 upregulated mRNAs for OCT-4, REX-1, telomerase reverse transcriptase, and hypoxia-inducible factor-1 alpha, and increased the expression of SSEA-4 compared to air [10].

Analytical, diagnostic and therapeutic context of REXO1

• The presence of a premature termination codon in the Tax1/Rex1 mRNA encoded by the full-length provirus was inferred from the presence of small Rex1-related polypeptides lacking C-terminal sequences and confirmed by sequence analysis [2].

References