Figure 5.

Model for Gas1 signaling via the proline-rich domain of p53. The proline-rich domain of p53 (dots indicate the four relevant prolines) may signal for growth suppression via contacting the SH3 domain of a cellular protein (X). Such interaction should be modulated by signals departing from the plasma membrane where Gas1 is localized. A p53 mutant lacking the tetramerization domain (competitor) could interfere with growth suppression by sequestering the cognate SH3-containing cellular protein.