Visualization of subcellular NAD pools and intra-organellar protein localization by poly-ADP-ribose formation

Poly-ADP-ribose polymerases (PARPs) use NAD⁺ as substrate to generate polymers of ADP-ribose. We targeted the catalytic domain of human PARP1 as molecular NAD⁺ detector into cellular organelles. Immunochemical detection of polymers demonstrated distinct subcellular NAD⁺ pools in mitochondria, peroxisomes and, surprisingly, in the endoplasmic reticulum and the Golgi complex. Polymers did not accumulate within the mitochondrial intermembrane space or the cytosol. We demonstrate the suitability of this compartment-specific NAD⁺ and poly-ADP-ribose turnover to establish intra-organellar protein localization. For overexpressed proteins, genetically endowed with PARP activity, detection of polymers indicates segregation from the cytosol and consequently intra-organellar residence. In mitochondria, polymer build-up reveals matrix localization of the PARP fusion protein. Compared to presently used fusion tags for subcellular protein localization, these are substantial improvements in resolution. We thus established a novel molecular tool applicable for studies of subcellular NAD metabolism and protein localization.     

Relaxin family peptide systems and the central nervous system

Since its discovery in the 1920s, relaxin has enjoyed a reputation as a peptide hormone of pregnancy. However, relaxin and other relaxin family peptides are now associated with numerous non-reproductive physiologies and disease states. The new millennium bought with it the sequence of the human genome and subsequently new directions for relaxin research. In 2002, the ancestral relaxin gene RLN3 was identified from genome databases. The relaxin-3 peptide is highly expressed in a small region of the brain and in species from teleost to primates and has both conserved sequence and sites of expression. Combined with the discovery of the relaxin family peptide receptors, interest in the role of the relaxin family peptides in the central nervous system has been reignited. This review explores the relaxin family peptides that are expressed in or act upon the brain, the receptors that mediate their actions, and what is currently known of their functions.     

Some milestones in the study of hydrocarbon flames

Nach einigen einleitenden Bemerkungen zur Bedeutung von Fachzeitschriften für die Entwicklung der Wissenschaften und einem Hinweis auf die wichtigsten Abschnitte des Lebenslaufes von August Leopold Crelle (1780–1855) wird seine herausragende Rolle als Gründer und Herausgeber wissenschaftlicher Fachzeitschriften gewürdigt. Zunächst wird die dabei von Crelle besonders für das Journal für die reine und angewandte Mathematik geleistete Arbeit ausführlicher dargestellt, dem sich der Versuch einer Einschätzung der Bedeutung dieser Zeitschrift mit Hilfe quantitativer Kennziffern anschließt. Schließlich wird die Bedeutung des gleichfalls von Crelle begründeten Journals für die Baukunst untersucht und herausgearbeitet, daß durch das Baujournal den deutschen Ingenieuren wichtige Informationen und Erfahrungen aus dem technisch fortgeschrittenerem Ausland übermittelt wurden. Abschließend werden fünf unveröffentlichte Dokumente im Wortlaut wiedergegeben, die mit der vorstehenden Thematik im Zusammenhang stehen.