Initiation of proliferation but not of differentiation was followed by a 20- to 25-fold increase in the nuclear level of the DNA polymerase-associated processivity factor PCNA and of the proliferation-specific transcription factor E2F1 .
initiation of proliferation but not of differentiation was followed by a 20- to 25-fold increase in the nuclear level of the dna polymerase-associated processivity factor pcna and of the proliferation-specific transcription factor e2f1 .
O O B-other_name O O O B-other_name O O O O O O O O O O O O O O B-protein_molecule I-protein_molecule I-protein_molecule I-protein_molecule B-protein_molecule O O O B-protein_molecule I-protein_molecule I-protein_molecule B-protein_molecule O