Cyclin B1 [CCNB1/1098]

Primary Antibodies

Cyclins are a family of proteins that activate
specific cyclin-dependent kinases required for progression
through the cell cycle. The entry of all eukaryotic cells
into mitosis is regulated by activation of cdc2/cdk1 at the
G2/M transition. This activation is a multi-step process that
begins with the binding of the regulatory subunit, cyclin B1,
to cdc2/cdk1 to form the mitosis-promoting factor (MPF).
MPF remains in the inactive state until phosphorylation of
cdc2/cdk1 at Thr161 by cdk activating kinase (CAK) (1, 2)
and dephosphorylation of cdc2/cdk1 at Thr14/Tyr15 by
cdc25C. Five cyclin B1 phosphorylation sites (Ser116,
126, 128, 133, and 147) are located in the cytoplasmic
retention signal (CRS) domain and are thought to regulate
the translocation of cyclin B1 to the nucleus at the G2/M
checkpoint, promoting nuclear accumulation and initiation
of mitosis. While MPF itself can phosphorylate Ser126
and Ser128, polo-like kinase 1 (PLK1) phosphorylates
cyclin B1 preferentially at Ser133 and possibly at Ser147. At the end of mitosis, cyclin B1 is targeted for degradation by the anaphase-promoting complex (APC), allowing for cell cycle progression. Research studies have shown that cyclin B1 is overexpressed in breast, prostate, and non-small cell lung cancer.

Tonsil, SqCC

50-200