Dictyostelium starvation / growth-to-development initiation

The switch that commits starving Dictyostelium discoideum cells to development. Two inputs converge. (1) Density sensing: growing and early-starving cells secrete conditioned-medium factor (CMF, cmfA); only when CMF accumulates above a threshold (i.e. enough cells are present) can cells respond to cAMP pulses and aggregate, coupling cell density to developmental onset. (2) The growth-to-development kinase: on starvation the DYRK-family dual-specificity kinase YakA arrests the cell cycle and drives developmental initiation, in part by down-regulating the Pumilio-family translational repressor PufA; PufA normally binds the pkaC (PKA catalytic subunit) mRNA and represses its translation, so relieving PufA de-represses PKA-C, and rising PKA activity turns on early developmental gene expression and the cAMP-signalling machinery. The net YakA -| PufA -| pkaC logic is a double negative — YakA activates PKA. OUT OF SCOPE: the downstream cAMP relay (dicty_extracellular_camp_relay) and PKA's many later developmental roles; the CMF receptor CMFR1 (not yet reviewed). Phrased over functions and family selectors with D. discoideum representatives.

Dictyostelium-specific growth-to-development initiation module grounded to CMF (P34090), YakA (Q54QV3), PufA (Q54WA7) and PKA-C (P34099). GO molecular-function terms were taken from the completed DICDI reviews; nodes use PANTHER family selectors plus D. discoideum representative members, except CMF which has no PANTHER family and uses a GENE selector. The YakA -| PufA -| pkaC double-negative logic follows the pufA/yakA reviews. CMF is a parallel density-permission input. Named to signal Dictyostelium scope.