Gln222Arg (A2317G) polymorphism in the deoxyribonuclease I gene exhibits ethnic and functional differences.
BACKGROUND
The single nucleotide polymorphism (SNP) at deoxyribonuclease I (DNase I) in exon 8 (A2317G: Gln222Arg) has been shown to be associated with several diseases.


METHODS
The allele frequency of the DNASE1 polymorphism in Chinese (Shenyang and Guangzhou in China), Uygurs (Urumqi), Tamils (Sri Lanka), and Tibetans (Katmandu in Nepal) was investigated, and the results were compared with those of other studies.


RESULTS
This study revealed that DNASE1*1 is more common in Africans and DNASE1*2 is more common in Caucasians. Expression vectors of DNASE1*1 and DNASE1*2 were constructed and compared to the enzyme properties secreted into a medium from transfected COS-7 cells. The activity of the type-2 enzyme was significantly higher than that of the type-1 enzyme. In addition, the type-1 enzyme was heat-labile when compared to the type-2 enzyme. Moreover, the optimum pH of the DNase I type-2 enzyme was more acidic than that of DNase I type-1.


CONCLUSIONS
This study revealed that the distribution of Gln222Arg in the DNASE1 gene is different among ethnic groups and that the DNASE1 polymorphism appears to affect the specific activity, heat sensitivity, and optimum pH of the DNase I enzyme.
Takeshita
Haruo
H
Department of Legal Medicine, Shimane University School of Medicine, Izumo, Japan. htakeshi@med.shimane-u.ac.jp
Soejima
Mikiko
M
Koda
Yoshiro
Y
Yasuda
Toshihiro
T
Takatsuka
Hisakazu
H
Fujihara
Junko
J
D000818:Animals; D044466:Asian People / Q000235:genetics*; D019556:COS Cells; D002522:Chlorocebus aethiops; D003850:Deoxyribonuclease I / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D005787:Gene Frequency; D005828:Genetics, Population; D006801:Humans; D006863:Hydrogen-Ion Concentration; D020641:Polymorphism, Single Nucleotide
D003850:Deoxyribonuclease I