Telomeric localization of the modified DNA base J in the genome of the protozoan parasite Leishmania.
Nucleic Acids Res
; 35(7): 2116-24, 2007.
Article
em En
| MEDLINE
| ID: mdl-17329373
ABSTRACT
Base J or beta-d-glucosylhydroxymethyluracil is a DNA modification replacing a fraction of thymine in the nuclear DNA of kinetoplastid parasites and of Euglena. J is located in the telomeric sequences of Trypanosoma brucei and in other simple repeat DNA sequences. In addition, J was found in the inactive variant surface glycoprotein (VSG) expression sites, but not in the active expression site of T. brucei, suggesting that J could play a role in transcription silencing in T. brucei. We have now looked at the distribution of J in the genomes of other kinetoplastid parasites. First, we analyzed the DNA sequences immunoprecipitated with a J-antiserum in Leishmania major Friedlin. Second, we investigated the co-migration of J- and telomeric repeat-containing DNA sequences of various kinetoplastids using J-immunoblots and Southern blots of fragmented DNA. We find only approximately 1% of J outside the telomeric repeat sequences of Leishmania sp. and Crithidia fasciculata, in contrast to the substantial fraction of non-telomeric J found in T. brucei, Trypanosoma equiperdum and Trypanoplasma borreli. Our results suggest that J is a telomeric base modification, recruited for other (unknown) functions in some kinetoplastids and Euglena.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Uracila
/
Telômero
/
Glucosídeos
/
Leishmania
Limite:
Animals
Idioma:
En
Revista:
Nucleic Acids Res
Ano de publicação:
2007
Tipo de documento:
Article
País de afiliação:
Holanda