A common mechanism for protein cluster formation

Pattern formation of Rho GTPases in single cell wound healing

“…The general question—how is an initially crude signal (a local increase in calcium; Benink and Bement, 2005; Clark et al ., 2009) converted into more precisely ordered local signals such as the Rho GTPase zones?—is in essence the same question asked during embryonic pattern formation, in which initially broad, and broadly active, gradients of pattering information that span much of the system are progressively converted into narrow, and narrowly signaling, regions that may be just a few cells wide. This general similarity is consistent with the suggestion that the Rho GTPases be considered as core components of intracellular pattern formation systems, analogous to morphogens (Bement et al ., 2006; Goryachev, 2011), as well as recent work focused on determining how polarity is established after fertilization in Caenorhabditis elegans (Goehring et al ., 2011). Further, the finding of bistability in this system mirrors results obtained from analysis of BMP signaling in Drosophila (Wang and Ferguson, 2005; Umulis et al ., 2006), whereas the proposed model of zone segregation by Abr-dependent amplification of Rho and suppression of Cdc42 is reminiscent of the Notch–Delta signaling system in which Notch-based signaling drives both its own amplification and the local suppression of antagonistic pathways (Artavanis-Tsakonas et al ., 1999).…”