Recent coral facies of the Indian Ocean Coast of Somalia with an interim check list of corals

Summary From a study of two areas, Jesira and the Bajuni Archipelago, about 400 km apart, a general pattern can be established for the Recent facies, together with the morphological and taxonomic features of the corals. Present day coral development is characterized by true fringing reefs in the Bajuni Archipelago and by scattered patches and knolls in the Jesira area. The coral fauna, consisting of 27 genera and 63 species so far (including all uncertainties, but not sight records), is rather poor, though coral communities are locally well developed. These figures probably reflect incomplete study and sampling. Although comparison with other areas may therefore be premature, a preliminary biogeographical analysis suggests that this fauna is more closely related to that of the Red Sea than to East Africa and the Seychelles. This differs from other published biogeographical work on Indian Ocean coral faunas, but further study of the corals in this and neighbouring areas of the Indian Ocean is needed in order to resolve this apparent anomaly.     

Natural and Electroporation-Mediated Transformation of Methanococcus voltae Protoplasts

The lack of high-efficiency transformation systems has severely impeded genetic research on methanogenic members of the kingdom Archaeobacteria. By using protoplasts of Methanococcus voltae and an integration vector, Mip1, previously shown to impart puromycin resistance, we obtained natural transformation frequencies that were about 80-fold higher (705 transformants per μg of transforming DNA) than that reported with whole cells. Electroporation-mediated transformation of M. voltae protoplasts with covalently closed circular Mip1 DNA was possible, but at lower frequencies of ca. 177 transformants per μg of vector DNA. However, a 380-fold improvement (3,417 transformants per μg of DNA) over the frequency of natural transformation with whole cells was achieved by electroporation of protoplasts with linearized DNA. This general approach, of using protoplasts, should allow the transformation of other methanogens, especially those that may be gently converted to protoplasts as a result of their tendency to lyse in hypotonic solutions.     

Extraction and genetic control of two new water-soluble proteins of mature barley seed

This paper describes the genetic control of two new water-soluble proteins in barley. Water-soluble proteins (WSPs) of mature barley seed form part of the albumin/globulin class of seed proteins. They can be extracted from hand-milled grain with water, though some WSPs are more efficiently extracted with a solution of 10 mM dithiothreitol. Polymorphisms for WSPs were detected in isoelectric focusing gels incorporating various ampholine combinations. Two new controlling genes (Wsp4 andWsp5) have been identified and located using wheat/barley chromosome addition lines and barley doubled haploids.Wsp4 is located on chromosome 2 (2H), andWsp5 was found to be tightly linked toWsp2 on the long arm of chromosome 7 (5HL). Segregation of a sixth gene (Wsp6) is also described, but this has not been mapped. The results are discussed with respect to other previously mappedWsp loci.This work was funed by the Scottish Office of Agriculture and Fisheries Department and the Agricultural and Food Research Council.     

Synthesis,degradation, and subcellular localization of proteins encoded by the primary response genes TIS7/PC4 and TIS21/PC3

Murine TIS7 and TIS21 cDNAs were cloned from phorbol ester-induced Swiss 3T3 cells. The cognate rat cDNAs. PC4 and PC3, were cloned from nerve growth factor (NGF)-treated PC12 pheochromocytoma cells. The TIS7/PC4 and TIS21/PC3 primary response genes are rapidly and transiently induced in response to serum, phorbol esters, and polypeptide growth factors in quiescent Swiss 3T3 cells and by NGF and other ligands in PC12 cells. In both 3T3 and PC12 cells the appearance of the TIS21/PC3 message precedes that of TIS7/PC4 message following ligand stimulation, suggesting that the TIS21/PC3 protein is likely to be synthesized more rapidly than the TIS7/PC4 protein. Using antisera prepared against recombinant TIS21 and TIS7 proteins, we find that the TIS21/PC3 protein is, indeed, synthesized more rapidly than the TIS7/PC4 protein following stimulation in both 3T3 and PC12 cells. In addition, “pulse-chase” experiments demonstrate that the TIS21/PC3 protein is degraded much more rapidly than the TIS7/PC4 protein. The sequences of the predicted PC3 and PC4 proteins have lead to the speculation that these two proteins may both be secreted from cells following stimulation. The PC4 protein is reported to have some sequence similarity to interferons. The TIS21/PC3 protein contains a presumptive leader sequence. Using our antisera to the recombinant proteins, however, we cannot detect secretion of radiolabelled TIS7/PC4 or TIS21/PC3 protein. Immunohistochemical and subcellular fractionation experiments suggest that the TIS7 protein is a membrane associated, non-nuclear intracellular protein. The TIS21 protein, in contrast, is' a non-nuclear, soluble intracellular protein. © 1994 Wiley-Liss, Inc.     

Chromosome 4 controls potential water use efficiency ({delta}13C) in barley

By combining the approaches of whole-shoot carbon discriminationand genetic analysis, we found that chromosome 4 controls potentialwater use efficiency (     

Theoretical conformational analysis of the opioid δ antagonist H-Tyr-Tic-Phe-OH and the μ agonist H-Tyr-D-Tic-Phe-NH2

A molecular mechanics study (grid search and energy minimization) of the highly δ receptor-selective δ opioid antagonist H-Tyr-Tic-Phe-OH (TIP; Tic: tetrahydroisoquinoline-3-car-boxylic acid) resulted in four low energy conformers with energies within 2 kcal/mol of that of the lowest energy structure. These four conformers contain trans peptide bonds only and represent compact structures showing various patterns of aromatic ring stacking. The centrally located Tic residue imposes several conformational constraints on the N-terminal dipeptide segment; however, the results of molecular dynamics simulations indicated that this tripeptide still shows some structural flexibility, particularly at the Phe³ residue. Analogous studies performed with the structurally related μ receptor-selective μ agonist H-Tyr-D -Tic-Phe-NH₂ resulted in low energy structures that were also compact but showed patterns of ring stacking different from those obtained with TIP. Superim-position of low energy conformers of TIP and H-Tyr-D -Tic-Phe-NH₂ revealed that the Phe³ residues of the L -Tic- and the D -Tic peptide were always located on opposite sides of the plane defined by the Tic residue, thus providing an explanation for the distinct activity profiles of the two compounds in structural terms. Attempts to demonstrate spatial overlap between the pharmacophoric moieties of low energy conformers of TIP and the nonpeptide δ antagonist naltrindole were made by superimposing either the Tyr¹ and Tic² aromatic rings and the N-terminal amino group or the Tyr¹ and Phe³ aromatic rings and the N-terminal amino group of the peptide with the corresponding aromatic rings and nitrogen atom in the alkaloid structure. In each case a low energy structure of TIP was found that showed good spatial overlap of all three specified pharmacophoric groups. These two conformers may represent candidate structures for the δ receptor-bound conformation of TIP. © 1994 John Wiley & Sons, Inc.     

Conformational differences between cis and trans proline isomers of a peptide antigen representing the receptor binding domain of Pseudomonas aeruginosa as studied by 1H-nmr

A 17-residue disulfide-bridged peptide (PAK 128–144) corresponding to the C-terminus of Pseudomonas aeruginosa pilin strain K has been studied by one- and two-dimensional nmr techniques. This synthetic immunogen has been found to exist as two distinct conformations in solution, which have been demonstrated to arise as a result of the isomerization of the I¹³⁸-P¹³⁹ amide bond. The two isomers occur in the ratio of 3 : 1 trans to cis at 5°C. Sequential assignments for both forms have been accomplished through the use of nuclear Overhauser enhancement spectroscopy (NOESY) spectra and most side-chain resonances have been assigned using a combination of correlated spectroscopy, total correlated spectroscopy, and NOESY spectra. The presence of the cis isomer, which is considerably more predominant in the oxidized peptide, was confirmed by the observation of the characteristic NOEs between P¹³⁹ and the preceding residue. Further corroboration was given by the disappearance of the cis resonances in the spectrum of the P139A analogue of PAK 128–144. From observation of the differences in the chemical shifts and amide proton temperature coefficients of the two isomers, it is apparent that the two forms differ markedly in their solution conformation. The biological implications of the isomerization are discussed. © 1994 John Wiley & Sons, Inc.     

Activation of TNF-R1 receptor in the presence of copper kills TNF resistant CEM leukemic T cells

The cytotoxic effects of TNF on malignant cells are known to be mediated through high affinity surface receptors. The precise mechanism by which transformed cells are selectively killed by the activation of these receptors is yet unknown, but several intracellular signaling pathways are known to be involved. Phospholipase A2 activation by TNF-α has been shown to be important in the transduction of signals leading to cell death. We have used monitoring of extracellular acidification rate as a measure of cellular metabolism to follow the early time course of TNF effects on a human leukemic T cell line (CEM-SS cells). CEM-SS cells were relatively resistant to TNF cell killing but TNF caused an early stimulation of metabolism within 2-4 hr, followed by a suppression of metabolic activity occurring over 20 hr. In contrast, a TNF sensitive subclone of CEM cells (C1Ca) showed a rapid and dramatic decrease in metabolic activity corresponding to cytotoxicity within 18 hr. It was discovered that cupric o-phenanthroline markedly potentiated the effects of TNF on the resistant CEM-SS cells leading to cell death. This observation was specific for copper because ferric o-phenanthroline was without effect at the same concentration. The copper cytotoxic effect was shown to be mediated through the TNF-R1 receptor and independent of phospholipase A2 signaling. © 1994 Wiley-Liss, Inc.     

Phosphorylation and Palmitoylation of the Human D2L Dopamine Receptor in Sf9 Cells

Abstract: We have expressed and biochemically characterized the human D2_long (D2_L) dopamine receptor isoform using the baculovirus/Sf9 cell system. The expressed receptor bound ligands with a pharmacological profile similar to that reported for neuronal and cloned D2_L receptors expressed in mammalian cell lines. Dopamine binding to D2_L receptor was sensitive to guanine nucleotides, indicating receptor coupling to endogenous G proteins. A D2_L receptor-specific antibody identified two major protein species at ∼44 kDa and at ∼93 kDa in immunoblots, suggesting the presence of D2_L receptor monomers and dimers. Both species were purified by immunoprecipitation from digitonin-solubilized preparation of cells expressing D2_L receptor prelabeled with ³²P_i or [³H]-palmitate. These results constitute the first direct evidence for D2_L receptor phosphorylation and palmitoylation.