Association of c-myc protein with enzymes of DNA replication in high molecular weight fractions from mammalian cells.
Oncoprotein c-myc is expressed in proliferating but not quiescent mammalian cells, and its overexpression or inappropriate expression is associated with malignant transformation. However, in spite of an intense interest, the normal function of this protein has remained elusive. As a step towards the elucidation of the function of c-myc protein, we studied its distribution within several types of cells, including HL 60, K 562, COLO 320, and CHEF/18 cells. In all of the cells studied, c-myc protein was detected in high molecular weight protein fractions, in 350-600 Kd range, in gel-exclusion chromatography and sucrose gradient centrifugation. This distribution of c-myc protein coincided with the distribution of DNA polymerase alpha and several other enzymes necessary for DNA replication. The data suggest that c-myc product may be a component of the replitase complex of enzymes involved in nuclear DNA replication.
Studzinski
G P
GP
Department of Laboratory Medicine and Pathology, UMDNJ-New Jersey Medical School, Newark 07103.
Shankavaram
U T
UT
Moore
D C
DC
Reddy
P V
PV
D000818:Animals; D001345:Autoradiography; D002458:Cell Fractionation; D002499:Centrifugation, Density Gradient; D002850:Chromatography, Gel; D003110:Colonic Neoplasms / Q000378:metabolism / Q000473:pathology; D006224:Cricetinae; D003412:Cricetulus; D004257:DNA Polymerase II / Q000378:metabolism* / Q000502:physiology; D004261:DNA Replication / Q000502:physiology*; D004264:DNA Topoisomerases, Type I / Q000378:metabolism / Q000502:physiology; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D006801:Humans; D015151:Immunoblotting; D007942:Leukemia, Experimental / Q000378:metabolism / Q000473:pathology; D007951:Leukemia, Myeloid / Q000378:metabolism / Q000473:pathology; D008970:Molecular Weight; D016271:Proto-Oncogene Proteins c-myc / Q000378:metabolism*; D014407:Tumor Cells, Cultured
D016271:Proto-Oncogene Proteins c-myc; D004257:DNA Polymerase II; D004264:DNA Topoisomerases, Type I