RESUMEN
Centrosomes control cell motility, polarity and migration that is thought to be mediated by their microtubule-organizing capacity. Here we demonstrate that WNT signalling drives a distinct form of non-directional cell motility that requires a key centrosome module, but not microtubules or centrosomes. Upon exosome mobilization of PCP-proteins, we show that DVL2 orchestrates recruitment of a CEP192-PLK4/AURKB complex to the cell cortex where PLK4/AURKB act redundantly to drive protrusive activity and cell motility. This is mediated by coordination of formin-dependent actin remodelling through displacement of cortically localized DAAM1 for DAAM2. Furthermore, abnormal expression of PLK4, AURKB and DAAM1 is associated with poor outcomes in breast and bladder cancers. Thus, a centrosomal module plays an atypical function in WNT signalling and actin nucleation that is critical for cancer cell motility and is associated with more aggressive cancers. These studies have broad implications in how contextual signalling controls distinct modes of cell migration.
Asunto(s)
Aurora Quinasa B/metabolismo , Movimiento Celular , Centrosoma/metabolismo , Proteínas Cromosómicas no Histona/metabolismo , Proteínas Dishevelled/metabolismo , Neoplasias/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Vía de Señalización Wnt , Actinas/metabolismo , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Neoplasias de la Mama/metabolismo , Carcinoma de Células Transicionales/metabolismo , Línea Celular Tumoral , Humanos , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Proteínas de Microfilamentos/metabolismo , Pronóstico , Mapas de Interacción de Proteínas , Reacción en Cadena en Tiempo Real de la Polimerasa , Neoplasias de la Vejiga Urinaria/metabolismo , Proteínas de Unión al GTP rhoRESUMEN
Ryanodine receptors (RyRs) form calcium release channels located in the membranes of the sarcoplasmic and endoplasmic reticulum. RyRs play a major role in excitation-contraction coupling and other Ca(2+)-dependent signalling events, and consist of several globular domains that together form a large assembly. Here we describe the crystal structures of the SPRY1 and tandem-repeat domains at 1.2-1.5 Å resolution, which reveal several structural elements not detected in recent cryo-EM reconstructions of RyRs. The cryo-EM studies disagree on the position of SPRY domains, which had been proposed based on homology modelling. Computational docking of the crystal structures, combined with FRET studies, show that the SPRY1 domain is located next to FK506-binding protein (FKBP). Molecular dynamics flexible fitting and mutagenesis experiments suggest a hydrophobic cluster within SPRY1 that is crucial for FKBP binding. A RyR1 disease mutation, N760D, appears to directly impact FKBP binding through interfering with SPRY1 folding.
