Cytostatic factor: an activity that puts the cell cycle on hold.
Fertilization is the fundamental process in which two gametes - sperm and oocyte - fuse to generate a zygote that will form a new multicellular organism. In most vertebrates, oocytes await fertilization while arrested at metaphase of meiosis II. This resting state can be stable for many hours and depends on a cytoplasmic activity termed cytostatic factor (CSF). Recently, members of the novel Emi/Erp family of proteins have been put forward as important components of CSF. These proteins inhibit the anaphase-promoting complex/cyclosome (APC/C), which acts at the very core of the cell cycle regulatory machinery. Initially, Xenopus early mitotic inhibitor 1 (Emi1) was proposed to be a component of CSF, but newer work suggests that a structural relative, Emi-related protein 1 (Erp1/Emi2), is essential for maintenance of CSF arrest in Xenopus. Most importantly, studies on Erp1/Emi2 regulation have led to a detailed molecular understanding of the Ca2+-mediated release from CSF arrest that occurs upon fertilization.
Chemical Genetics, Independent Research Group, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany.
Andreas
A
Schmidt
Nadine R
NR
Rauh
Erich A
EA
Nigg
Thomas U
TU
Mayer
D064173:Anaphase-Promoting Complex-Cyclosome; D000818:Animals; D002453:Cell Cycle / Q000502:physiology*; D018797:Cell Cycle Proteins / Q000378:metabolism*; D005260:Female; D005306:Fertilization; D008540:Meiosis; D008954:Models, Biological; D009865:Oocytes; D017231:Proto-Oncogene Proteins c-mos / Q000378:metabolism*; D043743:Ubiquitin-Protein Ligase Complexes / Q000502:physiology; D014981:Xenopus / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*
D018797:Cell Cycle Proteins; D043743:Ubiquitin-Protein Ligase Complexes; D064173:Anaphase-Promoting Complex-Cyclosome; D017231:Proto-Oncogene Proteins c-mos