The distal sequence element of the selenocysteine tRNA gene is a tissue-dependent enhancer essential for mouse embryogenesis.
Appropriate expression of the selenocysteine tRNA (tRNA(Sec)) gene is necessary for the production of an entire family of selenoprotein enzymes. This study investigates the consequence of disrupting an upstream enhancer region of the mouse tRNA(Sec) gene (Trsp) known as the distal sequence element (DSE) by use of a conditional repair gene targeting strategy, in which a 3.2-kb insertion was introduced into the promoter of the gene. In the absence of DSE activity, homozygous mice failed to develop in utero beyond embryonic day 7.5 and had severely decreased levels of selenoprotein transcript. Cre-mediated removal of the selection cassette recovered DSE regulation of Trsp, restoring wild-type levels of tRNA(Sec) expression and allowing the generation of viable rescued mice. Further analysis of targeted heterozygous adult mice revealed that the enhancer activity of the DSE is tissue dependent since, in contrast to liver, heart does not require the DSE for normal expression of Trsp. Similarly, in mouse cell lines we showed that the DSE functions as a cell-line-specific inducible element of tRNA(Sec). Together, our data demonstrate that the DSE is a tissue-dependent regulatory element of tRNA(Sec) expression and that its activity is vital for sufficient tRNA(Sec) production during mouse embryogenesis.
Kelly
Vincent P
VP
Center for TARA, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba 305-8577, Japan. masi@tara.tsukuba.ac.jp
Suzuki
Takafumi
T
Nakajima
Osamu
O
Arai
Tsuyoshi
T
Tamai
Yoshitaka
Y
Takahashi
Satoru
S
Nishimura
Susumu
S
Yamamoto
Masayuki
M
D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D001483:Base Sequence; D004622:Embryo, Mammalian / Q000166:cytology / Q000201:enzymology; D047108:Embryonic Development / Q000235:genetics / Q000502:physiology; D004742:Enhancer Elements, Genetic / Q000235:genetics / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental; D018390:Gene Targeting; D005804:Genes, Lethal / Q000235:genetics; D005979:Glutathione Peroxidase / Q000235:genetics / Q000378:metabolism; D006419:Heme Oxygenase (Decyclizing) / Q000235:genetics / Q000378:metabolism; D051547:Heme Oxygenase-1; D008099:Liver / Q000378:metabolism; D008565:Membrane Proteins; D051379:Mice / Q000196:embryology* / Q000235:genetics; D008969:Molecular Sequence Data; D009206:Myocardium / Q000378:metabolism; D011506:Proteins / Q000235:genetics / Q000378:metabolism; D012345:RNA, Transfer, Amino Acid-Specific / Q000032:analysis / Q000235:genetics*; D051140:Selenoproteins; D014018:Tissue Distribution; D015854:Up-Regulation; D000094765:Glutathione Peroxidase GPX1
D000975:Antioxidants; D008565:Membrane Proteins; D011506:Proteins; D012345:RNA, Transfer, Amino Acid-Specific; D051140:Selenoproteins; C036928:tRNA, selenocysteine-; D005979:Glutathione Peroxidase; D006419:Heme Oxygenase (Decyclizing); D051547:Heme Oxygenase-1; C496542:Hmox1 protein, mouse; D000094765:Glutathione Peroxidase GPX1; C000722068:Gpx1 protein, mouse