Cloning of a cDNA encoding a rat DNase II-like acid DNase.
DNase II is a well-known deoxyribonuclease (DNase) that catalyzes the hydrolysis of DNA into oligonucleotides under acidic conditions. We have identified a novel DNase that shows homology to DNase II, named DLAD, from a search of an expressed sequence tag data base. The full-length cDNA for rat DLAD cloned by polymerase chain reaction encodes a 356-amino acid polypeptide containing a putative N-terminal signal peptide and 5 potential N-glycosylation sites; there is a predicted catalytic domain resemblance to rat DNase II. The predicted DLAD translation product shares 32.9% identity with DNase II. Interestingly, expression of the DRAD mRNA is highly restricted to the liver. A Myc-His tagged recombinant DLAD recovered mainly from the cytoplasm of transfected HeLa S3 cells has a divalent cation-independent DNase activity. The DLAD activity prefers acidic conditions to neutral. The recombinant protein expressed in HeLa S3 cells inhibits the expression of GFP- and lac Z-expression vectors, suggesting that DLAD may play a role in elimination of exogenous DNA. Identification of the full-length cDNA for DLAD would lead to an understanding of the physiology of this DNase II-like molecule.
Tanuma
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Department of Biochemistry, Faculty of Pharmaceutical Sciences, Science University of Tokyo, Japan. tanuma@ps.kagu.sut.ac.jp
Shiokawa
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D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics*; D003851:Deoxyribonucleases / Q000235:genetics*; D004706:Endodeoxyribonucleases / Q000235:genetics; D020224:Expressed Sequence Tags; D015870:Gene Expression; D049452:Green Fluorescent Proteins; D006367:HeLa Cells; D006801:Humans; D007763:Lac Operon; D008164:Luminescent Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D011994:Recombinant Proteins / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D014162:Transfection
D017931:DNA Primers; D018076:DNA, Complementary; D008164:Luminescent Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; D049452:Green Fluorescent Proteins; D003851:Deoxyribonucleases; D004706:Endodeoxyribonucleases; C019329:deoxyribonuclease II