Cell-cell contact and TGF-beta can arrest the cell cycle in G1. Mv1Lu mink epithelial cells
arrested by either mechanism are incapable of assembling active complexes containing the G1 …

We show that cyclin plays a pivotal role in the control of mitosis. A proteolysis-resistant mutant
of cyclin prevents the inactivation of maturation promoting factor and the exit from mitosis …

cdc25 controls the activity of the cyclin-p34cdc2 complex by regulating the state of tyrosine
phosphorylation of~ 34”~~~. Drosophila cdc25 protein from two different expression systems …

The gradual accumulation of cyclin in the frog egg induces an abrupt and concerted activation
of~ 34~~~~ that initiates mitosis. Activation is delayed even after the accumulation of …

We have used formaldehyde-mediated proteinDNA crosslinking within intact cells to examine
the in vivo chromatin structure of the D. melanogaster heat shock protein 70 (hsp70) genes…

The ability of cells to make exact replicas of themselves is central to the life and development
of complex organisms. Initial insights into the question of how cells divide came during the …

Formaldehyde (HCHO) produces DNA-protein crosslinks both in vitro and in vivo. Simian virus
40 (SV40) chromosomes that have been fixed by prolonged incubation with HCHO either …

Ubiquitin is a 76‐residue protein highly conserved among eukaryotes. Conjugation of ubiquitin
to intracellular proteins mediates their selective degradation in vivo. We describe a family …

Phosphorylation of p34cdc2 can both positively and negatively regulate its kinase activity.
We have mapped two phosphorylation sites in Xenopus p34cdc2 to Thr-14 and Tyr-15 within …

alpha-Protein is a high mobility group protein originally purified from African green monkey
cells based on its affinity for the 172-base-pair repeat of monkey alpha-satellite DNA. We …