S-phase-promoting factor

The S-phase-promoting factor (SPF) is a CDK-cyclin complex that induces the S-phase (synthesis phase) of the cell cycle.

Toward the end of the G1 phase of mitosis, an SPF is phosphorylated, causing a biochemical cascade that results in the activation of DNA replication proteins and the initiation of the G1/S transition.

See also

Cyclin
A (A1, A2) · B (B1, B2, B3) · D (D1, D2, D3) · E (E1, E2)
CDK
2 · 3 · 4 · 5 · 6 · 7 · 8 · 9 · 10 · CDK-activating kinase
CDK inhibitor
P53 p63 p73 family
p53 · p63 · p73
Phases and
checkpoints
Other cellular phases
B bsyn: dna (repl, cycl, reco, repr) · tscr (fact, tcrg, nucl, rnat, rept, ptts) · tltn (risu, pttl, nexn) · dnab, rnab/runp · stru (domn, 1°, 2°, 3°, 4°)