Checkpoints and restriction points in bacteria and eukaryotic cells.
Bacterial checkpoints, analogous to those proposed to exist in eukaryotic cells, offer insights into the definition of a checkpoint. Examination of bacterial "checkpoint" or arrest phenomena illustrate problems with a too-casual application of the checkpoint idea to eukaryotic phenomena. The question raised here is whether there are cellular processes that "check" whether a cellular process is completed. It is possible that many eukaryotic "checkpoints" may not have "checking" functions. Some of the ubiquitous checkpoint phenomena widely described may be merely the result of the inherent incompleteness of earlier events preventing the initiation of subsequent events.
Cooper
Stephen
S
Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan 48109-0620, USA. cooper@umich.edu
D000818:Animals; D001419:Bacteria / Q000166:cytology* / Q000378:metabolism*; D002453:Cell Cycle / Q000502:physiology*; D004261:DNA Replication; D005057:Eukaryotic Cells / Q000166:cytology* / Q000378:metabolism*; D008954:Models, Biological