Expression and sub-cellular localization of human ABH family molecules.
AlkB is an Escherichia coli protein that catalyses the oxidative demethylation of 1-methyladenine and 3-methylcytosine in DNA and RNA. The enzyme activity of AlkB is dependent on a 2-oxoglutarate- and Fe(II)-dependent (2OG-Fe[II]) oxygenase domain. Human AlkB homologues (hABH), hABH1, hABH2 and hABH3, which also possess the 2OG-Fe(II) oxygenase domain, have previously been identified. Recent bioinformatics analysis suggests the existence of an additional five ABH genes in humans. In this study, we identified the hABH4-hABH7 mRNAs and determined their expression in human tissues. Moreover, an hABH2 splice variant lacking the 2OG-Fe(II) oxygenase domain and a new gene, hABH8, were cloned from testis cDNA. hABH8 possesses not only the 2OG-Fe(II) oxygenase domain but both an RNA-binding motif and a methyl-transferase domain. mRNA of the eight hABH molecules was detected in the 16 normal human tissues examined. The sub-cellular localization of EmGFP-hABH8 was restricted to the cytoplasm. EmGFP-hABH1, 3, 4, 6 and 7 were localized in both the cytoplasm and nuclei. Interestingly, the EmGFP-hABH2 splice variant localized in nucleoplasm with a dot-like pattern. In some HeLa cells transfected with EmGFP-hABH5, dot-like fluorescence was also detected in the cytoplasm. These observations provide important information for the future annotation of the hABH family of molecules.
Tsujikawa
Kazutake
K
Department of Immunology, Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan. tujikawa@phs.osaka-u.ac.jp
Koike
Kazuhisa
K
Kitae
Kaori
K
Shinkawa
Aina
A
Arima
Hiroshi
H
Suzuki
Takashi
T
Tsuchiya
Mutsumi
M
Makino
Yasutaka
Y
Furukawa
Tatsuhiko
T
Konishi
Noboru
N
Yamamoto
Hiroshi
H
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D045643:DNA Repair Enzymes / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D018076:DNA, Complementary / Q000235:genetics; D020869:Gene Expression Profiling; D015971:Gene Expression Regulation, Enzymologic; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D015151:Immunoblotting; D008297:Male; D008969:Molecular Sequence Data; D021381:Protein Transport; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013347:Subcellular Fractions / Q000201:enzymology; D013737:Testis / Q000201:enzymology
D018076:DNA, Complementary; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D045643:DNA Repair Enzymes