title: Possible interaction between B1 retrotransposon-containing sequences and β(major) globin gene transcriptional activation during MEL cell erythroid differentiation.
abstract: Repetitive sequences consist of >50% of mammalian genomic DNAs and among these SINEs (short interspersed nuclear elements), e.g. B1 elements, account for 8% of the mouse genome. In an effort to delineate the molecular mechanism(s) involved in the blockade of the in vitro differentiation program of MEL (murine erythroleukaemia) cells by treatment with methylation inhibitors, we detected a DNA region of 559 bp in chromosome 7 located downstream of the 3'-end of the β(major) globin gene (designated B1-559) with unique characteristics. We have fully characterized this B1-559 region that includes a B1 element, several repeats of ATG initiation codons and consensus DNA-binding sites for erythroid-specific transcription factors NF-E2 (nuclear factor-erythroid-derived 2), GATA-1 and EKLF (erythroid Krüppel-like factor). Fragments derived from B1-559 incubated with nuclear extracts form protein complexes in both undifferentiated and differentiated MEL cells. Transient reporter-gene experiments in MEL and human erythroleukaemia K-562 cells with recombinant constructs containing B1-559 fragments linked to HS-2 (hypersensitive site-2) sequences of human β-globin gene LCR (locus control region) indicated potential cooperation upon erythropoiesis and globin gene expression. The possible interaction between the B1-559 region and β(major) globin gene transcriptional activation upon execution of erythroid MEL cell differentiation programme is discussed.
authors.affiliation: Laboratory of Pharmacology, Department of Pharmaceutical Sciences, Aristotle University of Thessaloniki, GR54124 Thessaloniki, Greece. ivizir@pharm.auth.gr
authors.forename: Ioannis S
authors.initials: IS
authors.lastname: Vizirianakis
authors.forename: Sotirios S
authors.initials: SS
authors.lastname: Tezias
authors.forename: Elsa P
authors.initials: EP
authors.lastname: Amanatiadou
authors.forename: Asterios S
authors.initials: AS
authors.lastname: Tsiftsoglou
mesh_terms: D000818:Animals; D001483:Base Sequence; D002454:Cell Differentiation; D045744:Cell Line, Tumor; D041905:Erythroid Cells / Q000166:cytology / Q000378:metabolism; D004920:Erythropoiesis; D050982:GATA1 Transcription Factor / Q000235:genetics / Q000378:metabolism; D017930:Genes, Reporter; D006801:Humans; D051741:Kruppel-Like Transcription Factors / Q000235:genetics / Q000378:metabolism; D004915:Leukemia, Erythroblastic, Acute / Q000378:metabolism; D019901:Locus Control Region; D051379:Mice; D008807:Mice, Inbred BALB C; D050984:NF-E2 Transcription Factor, p45 Subunit / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic; D018626:Retroelements / Q000235:genetics*; D015533:Transcriptional Activation; D055544:beta-Globins / Q000235:genetics / Q000378:metabolism*
chemical_list: D050982:GATA1 Transcription Factor; D051741:Kruppel-Like Transcription Factors; D050984:NF-E2 Transcription Factor, p45 Subunit; D018626:Retroelements; D055544:beta-Globins; C080774:erythroid Kruppel-like factor