University of Basel

About: University of Basel is a education organization based out in Basel, Basel-Stadt, Switzerland. It is known for research contribution in the topics: Population & Transplantation. The organization has 25084 authors who have published 52975 publications receiving 2388002 citations. The organization is also known as: Universität Basel & Basel University.

Mechanisms of motility in metastasizing cells.

Abstract: Cell migration and invasion are critical parameters in the metastatic dissemination of cancer cells and the formation of metastasis, the major cause of death in cancer patients. Migratory cancer cells undergo dramatic molecular and cellular changes by remodeling their cell-cell and cell-matrix adhesion and their actin cytoskeleton, molecular processes that involve the activity of various signaling networks. Although in the past years, we have substantially expanded our knowledge on the cellular and molecular processes underlying cell migration and invasion in experimental systems, we still lack a clear understanding of how cancer cells disseminate in metastatic cancer patients. Different types of cancer cell migration seem to exist, including single-cell mesenchymal or amoeboid migration and collective cell migration. In most epithelial cancers, loss of the cell-cell adhesion molecule E-cadherin and gain of mesenchymal markers and promigratory signals underlie the conversion of epithelial, differentiated cells to mesenchymal, migratory, and invasive cells, a process referred to as the epithelial-to-mesenchymal transition. Although solitary migrating epithelial cancer cells have mostly undergone epithelial-to-mesenchymal transition (mesenchymal migration), and sometimes even lose their cell-matrix adhesion (amoeboid migration), collective migration of cancer cells in cell sheets, clusters, or streams is also frequently observed. The molecular mechanisms defining the different modes of cancer cell migration remain in most parts to be delineated.

Structural basis of activity and allosteric control of diguanylate cyclase

Abstract: Recent discoveries suggest that a novel second messenger, bis-(3′→5′)-cyclic di-GMP (c-diGMP), is extensively used by bacteria to control multicellular behavior. Condensation of two GTP to the dinucleotide is catalyzed by the widely distributed diguanylate cyclase (DGC or GGDEF) domain that occurs in various combinations with sensory and/or regulatory modules. The crystal structure of the unorthodox response regulator PleD from Caulobacter crescentus, which consists of two CheY-like receiver domains and a DGC domain, has been solved in complex with the product c-diGMP. PleD forms a dimer with the CheY-like domains (the stem) mediating weak monomer–monomer interactions. The fold of the DGC domain is similar to adenylate cyclase, but the nucleotide-binding mode is substantially different. The guanine base is H-bonded to Asn-335 and Asp-344, whereas the ribosyl and α-phosphate moieties extend over the β2-β3-hairpin that carries the GGEEF signature motif. In the crystal, c-diGMP molecules are crosslinking active sites of adjacent dimers. It is inferred that, in solution, the two DGC domains of a dimer align in a two-fold symmetric way to catalyze c-diGMP synthesis. Two mutually intercalated c-diGMP molecules are found tightly bound at the stem–DGC interface. This allosteric site explains the observed noncompetitive product inhibition. We propose that product inhibition is due to domain immobilization and sets an upper limit for the concentration of this second messenger in the cell.

Reanimating Faces in Images and Video

Abstract: This paper presents a method for photo-realistic animation of any face shown in a single image or a video. The technique does not require example data of the person’s mouth movements, and the image to be animated is not restricted in pose and illumination. Video reanimation allows for head rotations and speech in the original sequence, yet neither of these motions is required. In order to animate novel faces, the system transfers mouth movements and expressions across individuals, based a common representation of different identities and facial expressions in a vector space of 3D shapes and textures. This space is computed from 3D scans of different neutral faces, and scans of facial expressions. The 3D model’s versatility with respect to pose and illumination is conveyed to photo-realistic image and video processing by a framework of analysis and synthesis algorithms: The system automatically estimates 3D shape, pose and other rendering parameters from single images, and tracks head pose and mouth movements in video. Reanimated with new mouth movements, the 3D face is rendered into the original images.