The KDEL receptor, ERD2, regulates intracellular traffic by recruiting a GTPase-activating protein for ARF1

The small GTPase ADP-ribosylation factor 1 (ARF1) is a key regulator of intracellular membrane traffic. Regulators of ARF1, its GTPase-activating protein (GAP) and its guanine nucleotide exchange factor have been identified recently. However, it remains uncertain whether these regulators drive the GTPase cycle of ARF1 autonomously or whether their activities can be regulated by other proteins. Here, we demonstrate that the intracellular KDEL receptor, ERD2, self-oligomerizes and interacts with ARF1 GAP, and thereby regulates the recruitment of cytosolic ARF1 GAP to membranes. Because ERD2 overexpression enhances the recruitment of GAP to membranes and results in a phenotype that reflects ARF1 inactivation, our findings suggest that ERD2 regulates ARF1 GAP, and thus regulates ARF1-mediated transport.     

Thrombolytic therapy in stroke. What do clinical tests prove?

Despite the increased risk of intracranial haemorrhage associated with the use of thrombolytic treatment of stroke. American studies have shown patients treated with rt-PA (recombinant plasminogen activator) within three hours of the onset of symptoms to manifest 30 per cent less disability at three-month follow-up than those placebo. However, until satisfactory criteria for the use of rt-PA are available, caution is essential, and thrombolytic therapy should be restricted to specialised centres. It is also important to promote public awareness of the stroke patient's need of immediate treatment at a specialised stroke unit.     

Psychosocial barriers to health promotion in an American Indian population

Northern Plains Indians (N = 200) completed the Indian Specific Health Risk Appraisal and measures assessing beliefs about risk factors and personal risk. Participants rated personal risk optimistically, judged their risk factor standing as superior to that of their peers, and neglected to consider risk factor standing when appraising personal risk. Moreover, participants were often not improving their standing on risk factors they considered relevant to their health. Such biases in health beliefs may prevent health interventions from being successful.