Characterization and function in vivo of two novel phospholipases B/lysophospholipases from Saccharomyces cerevisiae.

The yeast genome contains two genes, designated as PLB2 and PLB3, that are 67% and 62% identical, respectively, to PLB1, which codes for a phospholipase B/lysophospholipase in yeast (Lee, S. K., Patton, J. L., Fido, M., Hines, L. K., Kohlwein, S. D., Paltauf, F., Henry, S. A., and Levin, D. E. (1994) J. Biol. Chem. 269, 19725-19730). Deletion and overexpression studies and in vivo and in vitro activity measurements suggest that both genes indeed code for phospholipases B/lysophospholipases. In cell free extracts of a plb1 plb2 plb3 triple mutant, no phospholipase B activity was detectable. Upon overexpression of PLB2 in a plb1 plb3 mutant background, phospholipase B activity was detectable in the plasma membrane, periplasmic space extracts and the culture supernatant. Similar to Plb1p, Plb2p appears to accept all major phospholipid classes, with a preference for acidic phospholipids including phosphatidylinositol 3',4'-bisphosphate and phosphatidic acid. Consistent with a function as an extracellular lysophospholipase, PLB2 overexpression conferred resistance to lyso-phosphatidylcholine. Deletion of Plb2p function had no effect on glycerophosphoinositol or glycerophosphocholine release in vivo, in contrast to a deletion of Plb3p function, which resulted in a 50% reduction of phosphatidylinositol breakdown and glycerophosphoinositol release from the cells. In vitro, Plb3p hydrolyzes only phosphatidylinositol and phosphatidylserine and, to a lesser extent, their lyso-analogs. Plb3p activity in a plb1 plb2 mutant background was observed in periplasmic space extracts. Both Plb3p and Plb2p display transacylase activity in vitro, in the presence or absence, respectively, of detergent.     

Characterization of heterochromatin by sequential counterstain-enhanced fluorescence in three domestic bird species: Meleagris gallopavo, Columba livia domestica, and Anser anser L

The karyotypes of three avian species--Meleagris gallopavo, Anser anser L., and Columba livia domestica--were investigated by means of counterstain-enhanced fluorescence techniques (chromomycin A3/distamycin A/DAPI followed by DAPI/actinomycin D staining). A heterochromatin characterization of macro- and microchromosomes was performed. CMA3-positive (GC-rich) regions in the turkey included the telomeres of chromosomes 1, 3, 4, and Z. In the goose, the chromosome 2 was also CMA3-bright at the telomeres. The W chromosome possessed large amounts of CMA3-bright material on the short arm in both the turkey and the goose. Two types of centromeric heterochromatin were distinguished on acro- to telocentric chromosomes 6 to 14 in the pigeon. The microchromosomal heterochromation of the turkey and goose was GC-rich but had a high degree of variation. In the pigeon, several microchromosomes possessed predominantly AT-rich heterochromatin.     

A small,narrow-beaked albatross from the Pliocene of New Zealand demonstrates a higher past diversity in the feeding ecology of the Diomedeidae

We describe a nearly complete, three-dimensionally preserved skull of a new albatross species from the late Pliocene (3.0–3.4 million years ago) Tangahoe Formation of New Zealand. Aldiomedes angustirostris, n. gen. et sp. has only about 90% of the length of the skull of the smallest extant albatross and is the geologically youngest record of a small-sized albatross known to date. The new species is characterized by a mediolaterally compressed beak, which is not found in any living albatross. The small size and some cranial features of A. angustirostris indicate that, in spite of its comparatively young geological age, the new species was not part of crown group Diomedeidae. We hypothesize that A. angustirostris was more piscivorous than extant albatrosses, which predominantly feed on squid. The reasons for the extinction of smaller-sized albatrosses are elusive but may be related to changes in seabird fauna during the Pliocene epoch, which witnessed the radiation of various non-procellariiform seabird groups.     

Autophagy receptor CALCOCO2/NDP52 takes center stage in Crohn disease

To advance understanding of the complex genetics of Crohn disease (CD) we sequenced 42 whole exomes of patients with CD and five healthy control individuals, resulting in identification of a missense mutation in the autophagy receptor calcium binding and coiled-coil domain 2 (CALCOCO2/NDP52) gene. Protein domain modeling and functional studies highlight the potential role of this mutation in controlling NFKB signaling downstream of toll-like receptor (TLR) pathways. We summarize our recent findings and discuss the role of autophagy as a major modulator of proinflammatory signaling in the context of chronic inflammation.     

Steady-state kinetics of skeletal muscle myosin light chain kinase indicate a strong down regulation by products

The kinetic behaviour of myosin light chain kinase isolated from skeletal muscle was studied under steady-state conditions using highly purified phosphorylatable light chains 2 (LC2). Forward reaction, product inhibition, and reverse reaction data indicate a sequential mechanism which can be interpreted best by a rapid-equilibrium random bi-bi reaction model. The forward reaction parameters are KATP = 150 microM, KLC2 = 5.3 microM, and Ki LC2 = 7.6 microM. The enzyme forms a dead-end complex with ADP and light chain 2; Kd, ADP of this complex is 50 microM. The forward reaction is also strongly inhibited by the phosphorylated light chain 2, Ki, LC2P is 1.5 microM. An equilibrium constant Keq of about 70 can be calculated from the kinetic parameters which agrees with the directly measured value of about 60. The role of the two inhibitory mechanisms in the regulation of the enzyme and of the high energy of the light chain phosphate bond as deducible from Keq are discussed.     

Phylogenetic interrelationships of living and extinct Tinamidae,volant palaeognathous birds from the New World

Tinamous, one of the earliest diverging living avian lineages, consists of a Neotropical clade of palaeognathous birds with a fossil record limited to the early Miocene–Quaternary of southern South America. Here, we conduct a comprehensive, morphology‐based phylogenetic study of the interrelationships among extinct and living species of tinamous. Morphological data of fossil species are included in a matrix of 157 osteological and myological characters of 56 terminal taxa. The monophyly of most recognized genera is supported by the results of the analysis. The cladistic analysis also recovers the traditional subdivision between those tinamous specialized for open areas (Nothurinae) and those inhabiting forested environments (Tinaminae). Temporal calibration of the resultant phylogeny indicates that such a basal divergence had already taken place in the early Miocene, some 17 million years ago. The placement of the fossil species within the open‐area (Nothurinae) and the forest‐dwelling (Tinaminae) tinamous is also consistent with the palaeoenvironmental conditions inferred from the associated fauna. © 2014 The Linnean Society of London     

Oxygen transfer and scale-up in bioreactors using hydro-ejectors for gas-liquid contacting

The commonly used scale-up criteria are investigated for their applicability in the case of hydro-ejector reactors. In combination with the liquid jet momentum, which characterizes the hydro-ejector, a scale-up correlation with the oxygen transfer rate as scale-up criterion is proposed, independent of the type of hydro-ejector and the reactor configuration. The results with regard to the power input are compared with those of stirred tank and bubble column. Its competitiveness is at high power per volume input and above all in large scale reactors.