Mitochondrial ATP production is a well-known regulator of neuronal excitability. The reciprocal influence of plasma-membrane potential on ATP production, however, remains poorly understood. Here, we describe a mechanism by which depolarized neurons elevate the somatic ATP/ADP ratio in glutamatergic neurons.
View Article and Find Full Text PDFClearance of bacteria by macrophages involves internalization of the microorganisms into phagosomes, which are then delivered to endolysosomes for enzymatic degradation. These spatiotemporally segregated processes are not known to be functionally coupled. Here, we show that lysosomal degradation of bacteria sustains phagocytic uptake.
View Article and Find Full Text PDFHere, we evaluate the mechanisms underlying the neurodevelopmental deficits in Drosophila and mouse models of lysosomal storage diseases (LSDs). We find that lysosomes promote the growth of neuromuscular junctions (NMJs) via Rag GTPases and mechanistic target of rapamycin complex 1 (MTORC1). However, rather than employing S6K/4E-BP1, MTORC1 stimulates NMJ growth via JNK, a determinant of axonal growth in Drosophila and mammals.
View Article and Find Full Text PDFPresynaptic resting Ca(2+) influences synaptic vesicle (SV) release probability. Here, we report that a TRPV channel, Inactive (Iav), maintains presynaptic resting [Ca(2+)] by promoting Ca(2+) release from the endoplasmic reticulum in Drosophila motor neurons, and is required for both synapse development and neurotransmission. We find that Iav activates the Ca(2+)/calmodulin-dependent protein phosphatase calcineurin, which is essential for presynaptic microtubule stabilization at the neuromuscular junction.
View Article and Find Full Text PDFJ Am Soc Nephrol
February 2013
The insect nephrocyte and the mammalian glomerular podocyte are similar with regard to filtration, but it remains unclear whether there is an organ or cell type in flies that reabsorbs proteins. Here, we show that the Drosophila nephrocyte has molecular, structural, and functional similarities to the renal proximal tubule cell. We screened for genes required for nephrocyte function and identified two Drosophila genes encoding orthologs of mammalian cubilin and amnionless (AMN), two major receptors for protein reabsorption in the proximal tubule.
View Article and Find Full Text PDFThe immune system is vital for the immediate survival of multicellular organisms by protecting them from the damaging effects of bacterial infections, viruses, and toxic molecules. It has been hypothesized that the immune system plays a pivotal role in determining longevity. We investigated the efficiency of the innate immune system in Drosophila carrying the longevity extending mutations puc (JNK signaling pathway, stress response) and chico (insulin signaling pathway), as well as animals subjected to dietary restriction (DR), which also extends lifespan.
View Article and Find Full Text PDFThe innate immune response protects numerous organisms, including humans, from the universe of pathogenic molecules, viruses and micro-organisms. Despite its role in promoting pathogen resistance, inappropriate activation and expression of NFkappaB and other immunity-related effector molecules can lead to cancer, inflammation, and other diseases of aging. Understanding the mechanisms leading to immune system activation as well as the short- and long-term consequences of such activation on health and lifespan is therefore critical for the development of beneficial immuno-modulating and longevity-promoting interventions.
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