The occludin and ZO-1 complex, defined by small angle X-ray scattering and NMR, has implications for modulating tight junction permeability.

Tight junctions (TJs) are dynamic cellular structures that are critical for compartmentalizing environments within tissues and regulating transport of small molecules, ions, and fluids. Phosphorylation-dependent binding of the transmembrane protein occludin to the structural organizing protein ZO-1 contributes to the regulation of barrier properties; however, the details of their interaction are controversial. Using small angle X-ray scattering (SAXS), NMR chemical shift perturbation, cross-saturation, in vitro binding, and site-directed mutagenesis experiments.

Neonatal mortality of elk driven by climate, predator phenology and predator community composition.

1. Understanding the interaction among predators and between predation and climate is critical to understanding the mechanisms for compensatory mortality. We used data from 1999 radio-marked neonatal elk (Cervus elaphus) calves from 12 populations in the north-western United States to test for effects of predation on neonatal survival, and whether predation interacted with climate to render mortality compensatory.