Hommel's procedure in linear time

Hommel's and Hochberg's procedures for familywise error control are both derived as shortcuts in a closed testing procedure with the Simes local test. Hommel's shortcut is exact but takes quadratic time in the number of hypotheses. Hochberg's shortcut takes only linear time after the P‐values are sorted, but is conservative. In this paper, we present an exact shortcut in linear time on sorted P‐values, combining the strengths of both procedures. The novel shortcut also applies to a robust variant of Hommel's procedure that does not require the assumption of the Simes inequality.     

Nucleotide sequences of the genes encoding fructosebisphosphatase and phosphoribulokinase from Xanthobacter flavus H4-14

The genes encoding fructosebisphosphatase and phosphoribulokinase present on a 2.5 kb SalI fragment from Xanthobacter flavus H4-14 were sequenced. Two large open reading frames (ORFs) were identified, preceded by plausible ribosome-binding sites. The ORFs were transcribed in the same direction and were separated by 39 base pairs. They encoded proteins of 364 and 291 amino acids, with molecular masses of 38739 and 33409 Da, respectively. The ORFs were identified as the genes encoding FBPase and PRK, respectively, on the basis of similarity with FBPase and PRK sequences from other sources.     

The histochemical characterization of the coupling state of skeletal muscle mitochondria

Summary Isolated mitochondria from skeletal muscles of human and animals with neuromuscular diseases may reveal a loosely coupled state of oxidative phosphorylation, which is characterized by a normal phosphorylation in the presence of a phosphate acceptor and a maximal respiration in the absence of a phosphate acceptor. Moreover in these cases activity of mitochondrial Mg²⁺-stimulated ATPase is strongly increased and cannot be stimulated by the uncoupler 2,4-dinitrophenol. In this communication a histochemical technique for the demonstration of activity of mitochondrial Mg²⁺-stimulated ATPase to characterize the coupling state of muscle mitochondria in tissue sections, is described. This tissue-saving technique is especially suitable for the study of human skeletal muscle diseases.This paper is dedicated to Prof. Dr. med. W. Graumann in honour of his 65th birthday.     

Calmodulin in starfish oocytes. I. Calmodulin antagonists inhibit meiosis reinitiation

A heat-stable factor has been found in starfish (Patiria miniata and Marthasterias glacialis) oocytes that activates two calmodulin-dependent enzymes: bovine brain phosphodiesterase (10-fold increase) and sea urchin egg NAD-kinase (10- to 50-fold increase). The dose-response curves for activation of these enzymes were found to be parallel for the starfish egg extract and pure mammalian brain calmodulin. The active factor was purified by chromatography on DE 52 cellulose to which it remained bound and was eluted by 0.225 M ammonium sulfate. Active fractions were pooled, dialyzed, and run on a polyacrylamide gel. The starfish active factor comigrated with pure bovine brain calmodulin. A radioimmunoassay was performed on the purified factor; it cross-reacted with antibodies against pure calmodulin. That calmodulin may play a role in hormonally induced maturation of starfish oocytes is suggested by the fact that two calmodulin antagonists (trifluoperazine and vinblastine), which are also inhibitors of NAD-kinase, were found to block 1-methyladenine-induced oocyte maturation. The inhibition could be reversed by increasing the hormone concentration. Oocytes were sensitive to trifluoperazine only during the hormone-dependent period.     

Genetic Adaptation of Influenza A Viruses in Domestic Animals and Their Potential Role in Interspecies Transmission: A Literature Review

EcoHealth - In December 2011, the European Food Safety Authority awarded a Grant for the implementation of the FLURISK project. The main objective of FLURISK was the development of an...     

The Usp8 deubiquitination enzyme is post-translationally modified by tyrosine and serine phosphorylation

The ERBB1–ERBB4 receptors belong to a family of receptor tyrosine kinases that trigger a network of signaling pathways after ligand binding, thereby regulating cellular growth, differentiation and development. Ligand-induced signaling through ERBB1, also known as EGFR, is attenuated by the clathrin-dependent receptor-mediated endocytosis and RING E3-ligase Cbl-mediated receptor ubiquitination, which is followed by incorporation into multi-vesicular bodies (MVBs) and subsequent degradation in lysosomes. Before incorporation into MVBs, the EGFR is deubiquitinated by Usp8. We previously demonstrated that Usp8 is tyrosine phosphorylated in an EGFR- and SRC-kinase dependent manner. In the present study we show that overexpression of constitutively active SRC enhances constitutive and ligand-induced Usp8 tyrosine phosphorylation. We also show that enhanced endosomal recycling of the EGFR induced by TGFα stimulation is associated with decreased Usp8 tyrosine phosphorylation. We therefore hypothesize that tyrosine phosphorylation of Usp8 could regulate the function of Usp8. To identify Usp8 tyrosine phosphorylation site(s), we used Usp8 deletion constructs, site-directed mutagenesis of nine individual Usp8 tyrosine residues and mass spectrometry (MS) analysis. Our results demonstrate that the MIT-domain is necessary for ligand-induced tyrosine phosphorylation of Usp8 1–504. However, mutation of three MIT domain tyrosine residues did not abolish Usp8 tyrosine phosphorylation. Similar results were obtained upon mutation of six exposed tyrosine residues in the Rhod domain and linker region. Repeated MS analysis of both Usp8 WT and C748A mutants readily detected serine phosphorylation, including the S680 14–3–3 binding site, but did not reveal any phospho-tyrosine residues. Notably, mutation of the tyrosine residue in the Usp8 14–3–3 binding motif (Y679) did not abolish phosphoserine-dependent binding of 14–3–3 to Usp8. Our findings are most consistent with the model that MIT domain-dependent recruitment of Usp8 to endosomal membranes is important for low stoichiometry SRC-mediated tyrosine phosphorylation of multiple Usp8 tyrosines. Our findings demonstrate that Usp8 is a target for the post-translational serine and tyrosine phosphorylation, most likely characterized by low abundant tyrosine phosphorylation on multiple residues, and high abundant serine phosphorylation on several residues.