Temporal relationships of chromatin protein synthesis, DNA synthesis, and assembly of deoxyribonucleoprotein.
Chromatin assembly has been investigated in terms of the sites on DNA where newly synthesized chromatin proteins associate. Chromatin from cells labeled with [14C]-BrdUrd and [3H]lysine was fixed with formaldehyde and resolved in CsCl gradients. By varying the spacing of the labeling intervals of the two isotopes so as to encompass all possible periods in S-phase, the association of labeled, newly synthesized proteins on newly synthesized (BrdUrd-substituted) or preexisting chromatin DNA was determined. In all experiments it was found that newly synthesized chromatin proteins predominantly associated with nonreplicating DNA. Possible mechanisms by which cells recycle preexisting chromatin proteins to restore the protein content of newly synthesized DNA are discussed.
D001665:Binding Sites; D002455:Cell Division; D002843:Chromatin / Q000378:metabolism*; D004247:DNA / Q000096:biosynthesis / Q000378:metabolism*; D004261:DNA Replication; D003852:Deoxyribonucleoproteins / Q000378:metabolism*; D006367:HeLa Cells; D006657:Histones / Q000096:biosynthesis / Q000378:metabolism*; D009698:Nucleoproteins / Q000378:metabolism*; D013997:Time Factors
D002843:Chromatin; D003852:Deoxyribonucleoproteins; D006657:Histones; D009698:Nucleoproteins; D004247:DNA