Phosphorylation and chromatin mechanics: the central importance of substrate conformation in determining the patterns of HL-60 nuclear phosphorylation.
HL-60 nuclear autophosphorylation was studied in vitro under circumstances in which the conformation of chromatin was manipulated with both polyamines and DNAse-I. A general re-arrangement of the phosphorylation patterns occurred as polyamines were removed and nuclei were observed to expand. DNAse-I treatment reduced these phosphorylation patterns to a much simpler configuration indicating that the responding substrates were DNA-associated. It was concluded that substrate conformation was the main determining factor in the control of nuclear protein phosphorylation. These results suggest a method of general utility for the identification of truly nuclear proteins by the characteristics of their phosphate acceptor activity.
School of Biological Sciences, Flinders University of South Australia, Adelaide.
A
A
Testori
J D
JD
Skinner
A W
AW
Murray
L A
LA
Burgoyne
D002460:Cell Line; D002467:Cell Nucleus / Q000737:chemistry; D002843:Chromatin / Q000737:chemistry*; D003850:Deoxyribonuclease I; D004591:Electrophoresis, Polyacrylamide Gel; D009687:Nuclear Proteins / Q000737:chemistry*; D010766:Phosphorylation; D013095:Spermidine; D013096:Spermine; D013379:Substrate Specificity
D002843:Chromatin; D009687:Nuclear Proteins; D013096:Spermine; D003850:Deoxyribonuclease I; D013095:Spermidine