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Catalytic properties of DNA polymerase α activity associated with the heat‐stabilized nuclear matrix prepared from HeLa S3 cells
Author(s) -
Martelli Alberto M.,
Bareggi Renato,
Narducci Paola
Publication year - 1994
Publication title -
cell biochemistry and function
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.933
H-Index - 61
eISSN - 1099-0844
pISSN - 0263-6484
DOI - 10.1002/cbf.290120208
Subject(s) - dna polymerase , processivity , dna clamp , dna polymerase ii , dna polymerase delta , microbiology and biotechnology , polymerase , dna polymerase i , dna replication , dna , hela , dna synthesis , biochemistry , proliferating cell nuclear antigen , chemistry , biology , cell , polymerase chain reaction , reverse transcriptase , gene
We have investigated whether or not ATP or other nucleoside di‐ and trisphosphates (including some nonhydrolysable ATP analogues) can stimulate the activity and/or the processivity of DNA polymerase α associated with the nuclear matrix obtained from HeLa S3 cell nuclei that had been stabilized at 37°C prior to subfractionation, as has been reported previously for DNA polymerase α bound to the nuclear matrix prepared from 22‐h regenerating rat liver. We have found that HeLa cell matrix‐associated DNA polymerase α activity could not be stimulated at all by ATP or other nucleotides, a behaviour which was shared also by DNA polymerase α activity that solubilizes from cells during the isolation of nuclei and that is thought to be a form of the enzyme not actively engaged in DNA replication. Moreover, the processivity of matrix‐bound DNA polymerase α activity was low (< 10 nucleotides). These results were obtained with the matrix prepared with either 2 M NaCl or 0·25 M (NH 4 ) 2 SO 4 and led us to consider that a 37° incubation of isolated nuclei renders resistant to high‐salt extraction a form of DNA polymerase α which is unlikely to be involved in DNA replication in vivo .