Substrate recognition component of a SCF (SKP1-CUL1-F-box protein) E3 ubiquitin-protein ligase complex which mediates the ubiquitination and subsequent proteasomal degradation of target proteins. May target the cAMP phosphodiesterase regA for degradation leading to an increase in cAMP and PKA activity. Promotes development of prestalk cells as opposed to prespores within the developing fruiting body. Required for culmination and fruiting body development. Component of an SCF complex including at least culA. Formation of this complex appears to require activity of the MAP kinase erk2. Interacts with regA. Not expressed during vegetative growth. Expressed from around 4 hours following the induction of starvation. Expression peaks around 14 hours (first finger/slug stage), and drops around 18 hours (Mexican hat stage). Expressed at high levels in prestalk cells. Also expressed in spores that have risen to the top of the fruiting body and undergone encapsulation. Cells preferentially form spores within chimeric cell populations and are more likely to survive adverse conditions than their wild type counterparts, which accumulate preferentially within the stalk. Such mutants have been termed 'cheaters'. Over time, mutant cheaters may be expected to dominate mixed populations, as they ensure their own survival at the expense of their altruistic wild type counterparts. The spread of cheater mutants may be limited by the high degree of relatedness within naturally occurring populations of Dictyostelium discoideum. Altruistic behavior may be preserved from the damaging effects of mutant cheaters by the formation of clonal fruiting bodies, in which all cells exhibit cooperative behavior.