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Mutation of the GATA site in the erythroid cell–specific regulatory element of the ABO gene in a B m subgroup individual
Author(s) -
Nakajima Tamiko,
Sano Rie,
Takahashi Yoichiro,
Kubo Rieko,
Takahashi Keiko,
Kominato Yoshihiko,
Tsukada Junichi,
Takeshita Haruo,
Yasuda Toshihiro,
Uchikawa Makoto,
Isa Kazumi,
Ogasawara Kenichi
Publication year - 2013
Publication title -
transfusion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.045
H-Index - 132
eISSN - 1537-2995
pISSN - 0041-1132
DOI - 10.1111/trf.12181
Subject(s) - microbiology and biotechnology , electrophoretic mobility shift assay , biology , gata transcription factor , enhancer , transcription factor , gene , regulatory sequence , promoter , genetics , gene expression
Background The ABO blood group is important in blood transfusion. Recently, an erythroid cell–specific regulatory element has been identified in the first intron of ABO using luciferase reporter assays with K 562 cells. The erythroid cell–specific regulatory activity of the element was dependent upon GATA ‐1 binding. In addition, partial deletion of I ntron 1 including the element was observed in genomic DNAs obtained from 111 B m and AB m individuals, except for one, whereas the deletion was never found among 1005 individuals with the common phenotypes. Study Design and Methods In this study, further investigation was performed to reveal the underlying mechanism responsible for reduction of B antigen expression in the exceptional B m individual. Peptide nucleic acid–clamping polymerase chain reaction was carried out to amplify the B ‐related allele, followed by sequence determination. Electrophoretic mobility assays and promoter assays were performed to examine whether a nucleotide substitution reduced the binding of a transcription factor and induced loss of function of the element. Results Sequence determination revealed one point mutation of the GATA motif in the element. The electrophoretic mobility shift assays showed that the mutation abolished the binding of GATA transcription factors, and the promoter assays demonstrated complete loss of enhancer activity of the element. Conclusion These observations suggest that the mutation in the GATA motif of the erythroid‐specific regulatory element may diminish the binding of GATA transcription factors and down regulate transcriptional activity of the element on the B allele, leading to reduction of B antigen expression in erythroid lineage cells of the B m individual.