A unique DNA found in post-mitochondrial fraction from Ehrlich ascites tumor cells
Description
A DNA found in post-mitochondrial fractions from Ehrlich ascites cells, comprising 0.2% of the total cellular DNA, is partially characterized. It appears in cytoplasmic homogenates as a 14.6 S molecule, and is eluted from hydroxyapatite with 0.24 M sodium phosphate buffer. Its Cs2SO4 buoyant density is lower than Erlich ascites tumor nuclear DNA and it has low dG+dC content, as determined by chromatography of hydrolysates of 32P-labelled DNA. It is enriched in sequences which reassociate rapidly in the presence of excess nuclear DNA. It can be used as promoter for DNA synthesis by an endogenous DNA-dependent DNA polymerase found in association with the post-mitochondrial preparations. It is found to be associated with newly incorporated radioactivity following incubation in vitro with labelled UTP. Its localization in situ has not yet been attempled. It is thought to represent viral A-type particle associated, or plasma membrane associated DNA. (author)
Abstract (Portuguese)
Apresenta-se a caracterizacao parcial de um DNA encontrado em sedimentos pos-mitocondriais de celulas do tumor ascitico de Ehrlich. Esse DNA compoe 0,2% do DNA celular total e tem tamanho de 14,5 S, em homogenatos citoplasmicos. Sua eluicao de hidroxiapatita ocorre em tampao de fosfato de sodio 0,24M. Sua densidade de flotacao em Cs2SO4 e menor que a do DNA nuclear do tumor ascitico de Ehrlich e ele tem baixo conteudo de dG + dC, conforme determinado por cromatografia de hidrolisados apos marcacao por 32P. Ele e rico em sequencias que reassociam rapidamente na presenca de DNA nuclear em excesso. Ele pode ser usado como promotor de sintese de DNA por uma DNA polimerase dependente de DNA que e encontrada em associacao com os sedimentos pos-mitocondriais. Apos incubacao in vitro com UTP marcado, o DNA e encontrado associado com a radioatividade recem-incorporada. Nao se procedeu, ainda, a localizacao in situ do DNA. Postula-se que ele possa representar DNA associado a particulas viroticas tipo A ou DNA associado a membrana plasmatica. (autor)Additional details
Publishing Information
- Journal Title
- Revista Brasileira de Biologia
- Journal Volume
- 42
- Journal Issue
- 1
- Series
- Rev. Bras. Biol.
- Journal Page Range
- 181-192
- ISSN
- 0034-7108
- CODEN
- RBBIA
INIS
- Country of Publication
- Brazil
- Country of Input or Organization
- Brazil
- INIS RN
- 21086557
- Subject category
- S63: RADIATION, THERMAL, AND OTHER ENVIRONMENTAL POLLUTANT EFFECTS ON LIVING ORGANISMS AND BIOLOGICAL MATERIALS;
- Descriptors DEI
- DNA; LABELLED COMPOUNDS; NEOPLASMS; PHOSPHORUS 32
- Descriptors DEC
- BETA DECAY RADIOISOTOPES; BETA-MINUS DECAY RADIOISOTOPES; DAYS LIVING RADIOISOTOPES; DISEASES; ISOTOPES; LIGHT NUCLEI; NUCLEI; NUCLEIC ACIDS; ODD-ODD NUCLEI; ORGANIC COMPOUNDS; PHOSPHORUS ISOTOPES; RADIOISOTOPES