An Abundant Evolutionarily Conserved CSB-PiggyBac Fusion Protein Expressed in Cockayne Syndrome

Cockayne syndrome (CS) is a devastating progeria most often caused by mutations in the CSB gene encoding a SWI/SNF family chromatin remodeling protein. Although all CSB mutations that cause CS are recessive, the complete absence of CSB protein does not cause CS. In addition, most CSB mutations are located beyond exon 5 and are thought to generate only C-terminally truncated protein fragments. We now show that a domesticated PiggyBac-like transposon PGBD3, residing within intron 5 of the CSB gene, functions as an alternative 3′ terminal exon. The alternatively spliced mRNA encodes a novel chimeric protein in which CSB exons 1–5 are joined in frame to the PiggyBac transposase. The resulting CSB-transposase fusion protein is as abundant as CSB protein itself in a variety of human cell lines, and continues to be expressed by primary CS cells in which functional CSB is lost due to mutations beyond exon 5. The CSB-transposase fusion protein has been highly conserved for at least 43 Myr since the divergence of humans and marmoset, and appears to be subject to selective pressure. The human genome contains over 600 nonautonomous PGBD3-related MER85 elements that were dispersed when the PGBD3 transposase was last active at least 37 Mya. Many of these MER85 elements are associated with genes which are involved in neuronal development, and are known to be regulated by CSB. We speculate that the CSB-transposase fusion protein has been conserved for host antitransposon defense, or to modulate gene regulation by MER85 elements, but may cause CS in the absence of functional CSB protein

Control of bioflavour and safety in fermented sausages: first results of a European project.

Four types of fermented sausages were prepared: two using Northern technology (Norway and Belgium) and two using Mediterranean technology (Belgium and Italy). Mediterranean sausages showed higher pH values and highest residual amounts of myosin and actin. Free fatty acid concentrations reflected the nature of the raw material, rather than the ripening period. Italian sausages contained the highest amounts of hexanal. Norwegian sausages contained the highest amounts of both free fatty acids and free amino acids. Putrescine concentration could be related to initial contamination of raw materials. Mediterranean sausages were characterised by a 'pop corn' odour, identified as 2-acetyl-1-pyrroline. Proteolytic activity of pork Triceps brachii was found to be related to animal sex. Staphylococci and lactic acid bacteria were investigated. Leucine metabolism involving aldehyde production was found to be strain specific and very sensitive to pH and the presence of nitrite. Bacteria showed anti-oxidant activity, enhanced by the presence of manganese. Bacteriocin production by L. casei CTC 494 was studied and results incorporated into a mathematical model. (C) 2000 Elsevier Science Ltd

Control of bioflavour and safety in fermented sausages: first results of a European project

Four types of fermented sausages were prepared: two using Northern technology (Norway and Belgium) and two using Medi- terranean technology (Belgium and Italy). Mediterranean sausages showed higher pH values and highest residual amounts of myosin and actin. Free fatty acid concentrations re¯ected the nature of the raw material, rather than the ripening period. Italian sausages contained the highest amounts of hexanal. Norwegian sausages contained the highest amounts of both free fatty acids and free amino acids. Putrescine concentration could be related to initial contamination of raw materials. Mediterranean sausages were characterised by a ``pop corn'' odour, identi®ed as 2-acetyl-1-pyrroline. Proteolytic activity of pork Triceps brachii was found to be related to animal sex. Staphylococci and lactic acid bacteria were investigated. Leucine metabolism involving aldehyde production was found to be strain speci®c and very sensitive to pH and the presence of nitrite. Bacteria showed anti-oxidant activity, enhanced by the presence of manganese. Bacteriocin production by L. casei CTC 494 was studied and results incorporated into a mathema- tical model