c-myc protein and DNA replication: separation of c-myc antibodies from an inhibitor of DNA synthesis.
Antibodies against human c-myc protein have been reported to inhibit DNA polymerase activity and endogenous DNA synthesis in isolated nuclei, suggesting a role for c-myc in DNA replication. Using the same antibody preparations, we observed equivalent inhibition of simian virus 40 DNA replication and DNA polymerase alpha and delta activities in vitro, as well as inhibition of DNA synthesis in isolated nuclei. However, the c-myc antibodies could be completely separated from the DNA synthesis inhibition activity. c-myc antibodies prepared in other laboratories also did not interfere with initiation of simian virus 40 DNA replication, DNA synthesis at replication forks, or DNA polymerase alpha or delta activity. Therefore, the previously reported inhibition of DNA synthesis by some antibody preparations resulted from the presence of an unidentified inhibitor of DNA polymerases alpha and delta and not from the action of c-myc antibodies.
Gutierrez
C
C
Department of Cell Biology, Roche Institute of Molecular Biology, Hoffmann-La Roche Inc., Nutley, New Jersey 07110.
Guo
Z S
ZS
Farrell-Towt
J
J
Ju
G
G
DePamphilis
M L
ML
D000818:Animals; D000906:Antibodies / Q000302:isolation & purification*; D000911:Antibodies, Monoclonal / Q000302:isolation & purification*; D002460:Cell Line; D004257:DNA Polymerase II / Q000037:antagonists & inhibitors; D004258:DNA Polymerase III; D004261:DNA Replication; D004279:DNA, Viral / Q000096:biosynthesis; D006801:Humans; D007158:Immunologic Techniques; D007163:Immunosorbent Techniques; D019384:Nucleic Acid Synthesis Inhibitors; D011518:Proto-Oncogene Proteins / Q000276:immunology / Q000502:physiology*; D016271:Proto-Oncogene Proteins c-myc; D013539:Simian virus 40 / Q000235:genetics
D000906:Antibodies; D000911:Antibodies, Monoclonal; D004279:DNA, Viral; D019384:Nucleic Acid Synthesis Inhibitors; D011518:Proto-Oncogene Proteins; D016271:Proto-Oncogene Proteins c-myc; D004257:DNA Polymerase II; D004258:DNA Polymerase III