Publications by authors named "Ismene Fertschai"

Horned lizards () are specialized predators, including many species that primarily feed on seed harvester ants (). Harvester ants have strong mandibles to husk seeds or defensively bite, and a venomous sting. Texas horned lizards possess a blood plasma factor that neutralizes harvester ant venom and produce copious mucus in the pharynx and esophagus, thus embedding and incapacitating swallowed ants.

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Programmed cell death of lipid-laden macrophages is a prominent feature of atherosclerotic lesions and mostly ascribed to accumulation of excess intracellular cholesterol. The present in vitro study investigated whether intracellular triacylglycerol (TG) accumulation could activate a similar apoptotic response in macrophages. To address this question, we utilized peritoneal macrophages isolated from mice lacking adipose triglyceride lipase (ATGL), the major enzyme responsible for TG hydrolysis in multiple tissues.

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Store-operated Ca(2+) entry (SOCE) is established by formation of subplasmalemmal clusters of the endoplasmic reticulum (ER) protein, stromal interacting molecule 1 (STIM1) upon ER Ca(2+) depletion. Thereby, STIM1 couples to plasma membrane channels such as Orai1. Thus, a close proximity of ER domains to the plasma membrane is a prerequisite for SOCE activation, challenging the concept of local Ca(2+) buffering by mitochondria as being essential for SOCE.

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The significance and extent of Ca(2+) regulation of the biosynthetic secretory pathway have been difficult to establish, and our knowledge of regulatory relationships integrating Ca(2+) with vesicle coats and function is rudimentary. Here, we investigated potential roles and mechanisms of luminal Ca(2+) in the early secretory pathway. Specific depletion of luminal Ca(2+) in living normal rat kidney cells using cyclopiazonic acid (CPA) resulted in the extreme expansion of vesicular tubular cluster (VTC) elements.

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Mitochondrial Ca(2+) uptake is crucial for the regulation of the rate of oxidative phosphorylation, the modulation of spatio-temporal cytosolic Ca(2+) signals and apoptosis. Although the phenomenon of mitochondrial Ca(2+) sequestration, its characteristics and physiological consequences have been convincingly reported, the actual protein(s) involved in this process are unknown. Here, we show that the uncoupling proteins 2 and 3 (UCP2 and UCP3) are essential for mitochondrial Ca(2+) uptake.

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Imperfect synchrony between male calls occurs in the acoustically interacting bushcricket Mecopoda elongata, and males establishing the temporal leadership attract more females in choice experiments. An asymmetrical representation of leader and follower signals in pairs of direction-selective neurons of the auditory pathway was suggested to represent the neural basis for the preference of females. We investigated the time-intensity trading effect, which occurs when the temporal advantage of the leader signal is compensated, and can be reversed, by an additional sound pressure level of the follower.

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