dOCRL maintains immune cell quiescence in Drosophila by regulating endosomal traffic

Lowe Syndrome is a developmental disorder characterized by eye, kidney, and neurological pathologies, and is caused by mutations in the phosphatidylinositol-5-phosphatase OCRL. OCRL plays diverse roles in endocytic and endolysosomal trafficking, cytokinesis, and ciliogenesis, but it is unclear which of these cellular functions underlie specific patient symptoms. Here, we show that mutation of Drosophila OCRL causes cell-autonomous activation of hemocytes, which are macrophage-like cells of the innate immune system. Among many cell biological defects that we identified in docrl mutant hemocytes, we pinpointed the cause of innate immune cell activation to reduced Rab11-dependent recycling traffic and concomitantly increased Rab7-dependent late endosome traffic. Loss of docrl amplifies multiple immune-relevant signals, including Toll, Jun kinase, and STAT, and leads to Rab11-sensitive mis-sorting and excessive secretion of the Toll ligand Spåtzle. Thus, docrl regulation of endosomal traffic maintains hemocytes in a poised, but quiescent state, suggesting mechanisms by which endosomal misregulation of signaling may contribute to symptoms of Lowe syndrome

Enzymatic synthesis of optically pure cyanohydrins in microchannels using a crude cell lysate

\u3cp\u3eThe synthesis of optically pure cyanohydrins using a crude cell lysate containing the enzyme hydroxynitrile lyase (HNL) was studied in a microreactor in an aqueous-organic biphasic system. Different aldehyde substrates were selected to be converted to their corresponding cyanohydrins. It was successfully demonstrated that this crude cell lysate could readily be applied as a biocatalyst in a microchannel without clogging the channels. The biocatalytic activity toward the different substrates could rapidly be investigated with only small quantities of enzyme needed, compared to batch scale screening. Furthermore, the optimal contact between two immiscible phases in a microreactor resulted in enzymatic reactions with a high initial reaction rate and enantioselectivity, comparable to a batchwise process in which optimized conditions were achieved by vigorous stirring. Thus, performing the selected enzymatic reaction in a microreactor is a facile and cost efficient screening method leading to results which can be directly translated to batchwise processes.\u3c/p\u3