Molecular genetic basis of the histo-blood group ABO system

The histo-blood group ABO, the major human alloantigen system, involves three carbohydrate antigens (ABH). A, B and AB individuals express glycosyltransferase activities converting the H antigen into A or B antigens, whereas O(H) individuals lack such activity. Here we present a molecular basis for the ABO genotypes. The A and B genes differ in a few single-base substitutions, changing four amino-acid residues that may cause differences in A and B transferase specificity. A critical single-base deletion was found in the O gene, which results in an entirely different, inactive protein incapable of modifying the H antigen.     

Aberrant O-glycosylation and anti-glycan antibodies in an autoimmune disease IgA nephropathy and breast adenocarcinoma

Glycosylation abnormalities have been observed in autoimmune diseases and cancer. Here, we compare mechanisms of aberrant O-glycosylation, i.e., formation of Tn and sialyl-Tn structures, on MUC1 in breast cancer, and on IgA1 in an autoimmune disease, IgA nephropathy. The pathways of aberrant O-glycosylation, although different for MUC1 and IgA1, include dysregulation in glycosyltransferase expression, stability, and/or intracellular localization. Moreover, these aberrant glycoproteins are recognized by antibodies, although with different consequences. In breast cancer, elevated levels of antibodies recognizing aberrant MUC1 are associated with better outcome, whereas in IgA nephropathy, the antibodies recognizing aberrant IgA1 are part of the pathogenetic process.     

Na+,K+-ATPase as a docking station: protein–protein complexes of the Na+,K+-ATPase

The Na⁺,K⁺-ATPase, or sodium pump, is well known for its role in ion transport across the plasma membrane of animal cells. It carries out the transport of Na⁺ ions out of the cell and of K⁺ ions into the cell and thus maintains electrolyte and fluid balance. In addition to the fundamental ion-pumping function of the Na⁺,K⁺-ATPase, recent work has suggested additional roles for Na⁺,K⁺-ATPase in signal transduction and biomembrane structure. Several signaling pathways have been found to involve Na⁺,K⁺-ATPase, which serves as a docking station for a fast-growing number of protein interaction partners. In this review, we focus on Na⁺,K⁺-ATPase as a signal transducer, but also briefly discuss other Na⁺,K⁺-ATPase protein–protein interactions, providing a comprehensive overview of the diverse signaling functions ascribed to this well-known enzyme.     

Classification of micrococcus(Staphylococcus aureus) by means of differences in electro-phoretical mobility of extractable proteins

Zusammenfassung Mit Agar-Gel-Mikroelektrophorese war es möglich, typenspezifische Unterschiede in Mobilitäten von löslichen Proteinen der drei Typen,Staphylococcus aureus, «Cowan», zu demonstrieren. Diese Methode kann wahrscheinlich zur Typenbestimmung von Staphylococci und anderen Bakterien benützt werden.     

Combined effects of adrenaline and insulin on active electrogenic Na+-K+ transport in rat soleus muscle.

Both beta 2-adrenoreceptor stimulants (such as adrenaline and salbutamol) and insulin can increase active Na+-K+ transport and hyperpolarise skeletal cells. Thus, adrenaline and insulin, which are otherwise antagonistic regulators of several metabolic processes, have one action in common, namely, stimulation of active ion translocation. This is especially interesting as cyclic AMP stimulates Na+-K+ transport, whereas a lowering of the cytoplasmic concentration of cyclic AMP has been proposed as an early signal in the action of insulin. Here we report the results of experiments in which the active Na+-K+ transport and membrane potential (EM) of rat soleus muscles were studied during the action of supramaximal doses of insulin and beta 2-adrenoreceptor stimulants, alone and in combination. We conclude that the stimulant action of insulin on active electrogenic Na+-K+ transport is unlikely to be evoked by a lowering of the intracellular concentration of cyclic AMP.     

Unterliegt die Heimkehrgeschwindigkeit der Brieftauben hormonalen Einflüssen?

Summary The relation between the homecoming-speed of carrier-pigeons and the influence of sexhormones and prolaktin is reported.It is further examined whether the influence of prolaktin (breeding on 10–15 days old eggs) or psychological factors (feeding of young individuals of more than 15 days) are the factors, accelerating the homecoming-speed. Best results are obtained by combining breeding 1–6 days old eggs and feeding young pigeons of 2–3 weeks.

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In memoriam Heinz Knieriem zu seinem 15. Todestage     

Quantum storage of photonic entanglement in a crystal

Entanglement is the fundamental characteristic of quantum physics-much experimental effort is devoted to harnessing it between various physical systems. In particular, entanglement between light and material systems is interesting owing to their anticipated respective roles as 'flying' and stationary qubits in quantum information technologies (such as quantum repeaters and quantum networks). Here we report the demonstration of entanglement between a photon at a telecommunication wavelength (1,338?nm) and a single collective atomic excitation stored in a crystal. One photon from an energy-time entangled pair is mapped onto the crystal and then released into a well-defined spatial mode after a predetermined storage time. The other (telecommunication wavelength) photon is sent directly through a 50-metre fibre link to an analyser. Successful storage of entanglement in the crystal is proved by a violation of the Clauser-Horne-Shimony-Holt inequality by almost three standard deviations (S = 2.64?±?0.23). These results represent an important step towards quantum communication technologies based on solid-state devices. In particular, our resources pave the way for building multiplexed quantum repeaters for long-distance quantum networks.     

Structural basis for the regulated protease and chaperone function of DegP

All organisms have to monitor the folding state of cellular proteins precisely. The heat-shock protein DegP is a protein quality control factor in the bacterial envelope that is involved in eliminating misfolded proteins and in the biogenesis of outer-membrane proteins. Here we describe the molecular mechanisms underlying the regulated protease and chaperone function of DegP from Escherichia coli. We show that binding of misfolded proteins transforms hexameric DegP into large, catalytically active 12-meric and 24-meric multimers. A structural analysis of these particles revealed that DegP represents a protein packaging device whose central compartment is adaptable to the size and concentration of substrate. Moreover, the inner cavity serves antagonistic functions. Whereas the encapsulation of folded protomers of outer-membrane proteins is protective and might allow safe transit through the periplasm, misfolded proteins are eliminated in the molecular reaction chamber. Oligomer reassembly and concomitant activation on substrate binding may also be critical in regulating other HtrA proteases implicated in protein-folding diseases.