Most nerve axons of higher vertebrates are surrounded by a multilayered myelin membrane that is essential for promotion of rapid nerve conduction. A new study genetically uncouples the myelin-producing function of the myelinating cells from their role in axonal survival, suggesting that neurodegenerative disorders characterized by axonal loss might result from defects in the myelinating cells whether myelin irregularities are apparent or not.

Helicobacter pylori induces chronic gastritis in virtually all hosts, yet only a fraction of colonized patients ever develop peptic ulcer disease. A new study shows that binding of the H. pylori virulence determinant VacA by a receptor tyrosine phosphatase, Ptprz, modifies the phosphorylation pattern of gastric epithelial cell proteins and leads to cellular detachment. As activation of Ptprz also results in gastric injury and ulceration in vivo, these findings help explain why VacA-expressing strains of H. pylori augment the risk for peptic ulcer disease

Fibrillin controls TGF- activation

Secreted transforming growth factor-s (TGF-s) are rendered biologically inactive by binding proteins that also target and concentrate them to the extracellular matrix. Specific, but still poorly understood, activation is required for disassembly of the extracellular matrix–bound protein complex to liberate the mature growth factor and to obtain a correct biological effect. A new study shows that fibrillin-1, the protein defective in Marfan syndrome, has a biologically important role in controlling TGF- activation in the lung.

Genes that are expressed from a single allele in a random manner have one allele replicated earlier than the other. A new study shows that this replication asynchrony is coordinated within chromosome pairs.