We extend a model for the morphology and dynamics of a crawling eukaryotic cell to describe cells on micropatterned substrates. This model couples cell morphology, adhesion, and cytoskeletal flow in response to active stresses induced by actin and myosin. We propose that protrusive stresses are only generated where the cell adheres, leading to the cell's effective confinement to the pattern. Co...

Multicellular animals have evolved conserved signaling pathways that translate cell polarity cues into mitotic spindle positioning to control the orientation of cell division within complex tissue structures. These oriented cell divisions are essential for the development of cell diversity and the maintenance of tissue homeostasis. Despite intense efforts, the molecular mechanisms that control ...

Embryology and genetics have given rise to a mechanistic framework that explains the architecture of a developing organism. Until recently, however, such studies suffered from a lack of quantification and real-time visualization at the subcellular level, limiting their ability to monitor the dynamics of developmental processes. Live imaging using fluorescent proteins has overcome these limitati...

A. Veglio, 2 A. Gamba, 2 M. Nicodemi, F. Bussolino, and G. Serini Department of Oncological Sciences and Division of Molecular Angiogenesis, Institute for Cancer Research and Treatment, University of Torino School of Medicine, Candiolo (TO), Italy. CNISM, Corso Duca degli Abruzzi 24, 10125 Torino, Italy. Politecnico di Torino, Corso Duca degli Abruzzi 24, 10125 Torino, Italy; and INFN Torino, I...

Cellular polarization is often a response to distinct extracellular or intracellular cues, such as nutrient gradients or cortical landmarks. However, in the absence of such cues, some cells can still select a polarization axis at random. Positive feedback loops promoting localized activation of the GTPase Cdc42p are central to this process in budding yeast. Here, we explore spontaneous polariza...

Neurons in the developing mammalian brain are generated from progenitor cells in the proliferative ventricular zone, and control of progenitor division is essential to produce the correct number of neurons during neurogenesis. Here we establish that Gbetagamma subunits of heterotrimeric G proteins are required for proper mitotic-spindle orientation of neural progenitors in the developing neocor...

Proteins residing at the plus and minus ends of microtubules have been thought not to communicate with each other, but recent findings on bona fide nucleation factors also regulating microtubule dynamics have challenged this notion. New work by Bouissou et al (2014) in The EMBO Journal now reveals that interplay between the nucleation factor γ‐TuRC and the plus‐end tracking protein EB1 controls...

Phylogenetic analyses of toxin gene families have revolutionised our understanding of the origin and evolution of reptile venoms, leading to the current hypothesis that venom evolved once in squamate reptiles. However, because of a lack of homologous squamate non-toxin sequences, these conclusions rely on the implicit assumption that recruitments of protein families into venom are both rare and...

How cells form global, self-organized structures using genetically encoded molecular rules remains elusive. Here, we take a synthetic biology approach to investigate the design principles governing cell polarization. First, using a coarse-grained computational model, we searched for all possible simple networks that can achieve polarization. All solutions contained one of three minimal motifs: ...

New findings reveal that, in Caenorhabditis elegans embryos, the centrosome provides signals that induce cell polarization, independently of its function as the microtubule-organizing center.