Cyclin B3 is a dominant fast-acting cyclin that drives rapid early embryonic mitoses.
J Cell Biol
; 223(11)2024 Nov 04.
Article
in En
| MEDLINE
| ID: mdl-39105756
ABSTRACT
Mitosis in early embryos often proceeds at a rapid pace, but how this pace is achieved is not understood. Here, we show that cyclin B3 is the dominant driver of rapid embryonic mitoses in the C. elegans embryo. Cyclins B1 and B2 support slow mitosis (NEBD to anaphase â¼600 s), but the presence of cyclin B3 dominantly drives the approximately threefold faster mitosis observed in wildtype. Multiple mitotic events are slowed down in cyclin B1 and B2-driven mitosis, and cyclin B3-associated Cdk1 H1 kinase activity is â¼25-fold more active than cyclin B1-associated Cdk1. Addition of cyclin B1 to fast cyclin B3-only mitosis introduces an â¼60-s delay between completion of chromosome alignment and anaphase onset; this delay, which is important for segregation fidelity, is dependent on inhibitory phosphorylation of the anaphase activator Cdc20. Thus, cyclin B3 dominance, coupled to a cyclin B1-dependent delay that acts via Cdc20 phosphorylation, sets the rapid pace and ensures mitotic fidelity in the early C. elegans embryo.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Caenorhabditis elegans
/
Caenorhabditis elegans Proteins
/
Embryo, Nonmammalian
/
Cyclin B1
/
Mitosis
Limits:
Animals
Language:
En
Journal:
J Cell Biol
Year:
2024
Document type:
Article
Affiliation country:
Estados Unidos
Country of publication:
Estados Unidos