Cytochalasin B inhibition of endothelial proliferation at wound edges in vitro

Cytochalasin B prevents both migration and wound-associated replication when applied to wounded monolayers of bovine endothelium in tissue culture. The normal low background rate of replication in undisturbed areas of the cultures is not inhibited by cytochalasin B. These results suggest that some form of movement may be required for initiation of wound-associated replication by endothelial cells.     

Allele-specific modification of the expression of the adh2 gene in maize by ethylene

The effect of ethylene on the induction of alcohol dehydrogenase-2 in seedling roots of maize is reported. Allele-specific differences are observed in the response to the hormone. Hormonal treatment acts to eliminate the difference in gene expression that is characteristic of the alleles in untreated roots.     

Integrating adhesion, protrusion, and contraction during cell migration

Cell migration is fastest when the strength of the adhesion between the cell and the substrate is neither too strong nor too weak. In this issue of Cell, reveal how adhesion and cytoskeletal dynamics are integrated to optimize migration speed.     

Structural and functional analysis of Nup133 domains reveals modular building blocks of the nuclear pore complex

Nucleocytoplasmic transport occurs through nuclear pore complexes (NPCs) whose complex architecture is generated from a set of only approximately 30 proteins, termed nucleoporins. Here, we explore the domain structure of Nup133, a nucleoporin in a conserved NPC subcomplex that is crucial for NPC biogenesis and is believed to form part of the NPC scaffold. We show that human Nup133 contains two domains: a COOH-terminal domain responsible for its interaction with its subcomplex through Nup107; and an NH2-terminal domain whose crystal structure reveals a seven-bladed beta-propeller. The surface properties and conservation of the Nup133 beta-propeller suggest it may mediate multiple interactions with other proteins. Other beta-propellers are predicted in a third of all nucleoporins. These and several other repeat-based motifs appear to be major elements of nucleoporins, indicating a level of structural repetition that may conceptually simplify the assembly and disassembly of this huge protein complex.