DNA-protein cross-linking in nuclei of immature and mature chicken erythrocytes.
DNA-protein cross-linkages were formed in isolated nuclei from immature and mature chicken erythrocytes by reaction with cis-diammine dichloroplatinum. On the basis of electrophoretic behaviour, the most abundant proteins involved in the cross-linking appeared to be present also in preparations of nuclear matrix. The maturation of the erythrocyte, which is accompanied by transcriptional inactivation, leads to a decrease in the amount of DNA-interacting proteins, to a loss of proteins capable of a specific recognition of DNA sequences and, unexpectedly, to the appearence of some new DNA-protein interactions. At least three cross-linked proteins were found predominantly or exclusively in nuclei of immature cells, and three others in those of mature ones. The three DNA-bound proteins, typical of mature erythrocytes, were not found among the components of a high-salt preparation of nuclear matrix. The results obtained suggest that, in addition to the well-known histone H5 and MENT protein, these newly identified DNA-bound proteins contribute to the formation of the condensed, inactive chromatin characteristic of mature erythrocyte.
Department of Biochemical Sciences Alessandro Rossi Fanelli and Center of Molecular Biology of CNR, University La Sapienza, Rome, Italy.
M
M
Eufemi
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A
Ferraro
F
F
Altieri
L
L
Cervoni
C
C
Turano
D000818:Animals; D034961:Antigens, Nuclear; D000970:Antineoplastic Agents / Q000378:metabolism; D015153:Blotting, Western; D002467:Cell Nucleus / Q000737:chemistry; D002645:Chickens / Q000097:blood*; D002843:Chromatin / Q000737:chemistry; D002945:Cisplatin / Q000378:metabolism; D003432:Cross-Linking Reagents / Q000378:metabolism; D004247:DNA / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000032:analysis* / Q000378:metabolism; D015180:Electrophoresis, Gel, Two-Dimensional; D004912:Erythrocytes / Q000737:chemistry* / Q000648:ultrastructure; D009687:Nuclear Proteins / Q000032:analysis / Q000378:metabolism
D034961:Antigens, Nuclear; D000970:Antineoplastic Agents; D002843:Chromatin; D003432:Cross-Linking Reagents; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D004247:DNA; D002945:Cisplatin