ABSTRACT
The life cycle of eukaryotic cells is divided into four periods based on two landmarks, cell division at mitosis (M) and chromosomal DNA replication in S phase. Studies in this laboratory have for some years been dedicated to identifying cell cycle specific proteins that may be components of the pathways that regulate cell proliferation in human cells. Cyclin is a proliferation sensitive and cell cycle regulated nuclear protein. Studies by Bravo and Celis using high resolution two-dimensional gel electrophoresis were among the first to identify proliferation sensitive proteins that may be cell cycle regulated. The chapter the identification of the DNA replication and cell cycle regulated nuclear protein cyclin also called proliferating cell nuclear antigen, or the auxiliary protein of DNA polymerase d.
