The molecular machinery required for autophagy is highly conserved in all eukaryotes as seen by the high degree of conservation of proteins involved in the formation of the autophagosome membranes. Recently, both yeast Apg8p and its rat homologue Map1lc3 were identified as essential constituents of autophagosome membrane as a processed form. In addition, both the yeast and human proteins exist in two modified forms produced by a series of post-translational modifications including a critical C-terminal cleavage after a conserved Gly residue, and the smaller processed form is associated with the autophagosome membranes. Herein, we report the identification and characterization of three human orthologs of the rat Map1LC3, named MAP1LC3A, MAP1LC3B, and MAP1LC3C. We show that the three isoforms of human MAP1LC3 exhibit distinct expression patterns in different human tissues. Importantly, we found that the three isoforms of MAP1LC3 differ in their post-translation modifications. Although MAP1LC3A and MAP1LC3C are produced by the proteolytic cleavage after the conserved C-terminal Gly residue, like their rat counterpart, MAP1LC3B does not undergo C-terminal cleavage and exists in a single modified form. The essential site for the distinct posttranslation modification of MAP1LC3B is Lys-122 rather than the conserved Gly-120. Subcellular localization by cell fractionation and immunofluorescence revealed that three human isoforms are associated with membranes involved in the autophagic pathway. These results revealed different regulation of the three human isoforms of MAP1LC3 and implicate that the three isoforms may have different physiological functions.

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Bacteriocins are ribosomally synthesized peptides with antimicrobial activity produced by numerous bacteria. A novel bacteriocin-producing strain, Lactobacillus plantarum JLA-9, isolated from Suan-Tsai, a traditional Chinese fermented cabbage, was screened and identified by its physiobiochemical characteristics and 16S rDNA sequence analysis. A new bacteriocin, designated plantaricin JLA-9, was purified using butanol extraction, gel filtration, and reverse-phase high-performance liquid chromatography. The molecular mass of plantaricin JLA-9 was shown to be 1044 Da by MALDI-TOF-MS analyses. The amino acid sequence of plantaricin JLA-9 was predicted to be FWQKMSFA by MALDI-TOF-MS/MS, which was confirmed by Edman degradation. This bacteriocin exhibited broad-spectrum antibacterial activity against Gram-positive and Gram-negative bacteria, especially Bacillus spp., high thermal stability (20 min, 121 °C), and narrow pH stability (pH 2.0-7.0). It was sensitive to α-chymotrypsin, pepsin, alkaline protease, and papain. The mode of action of this bacteriocin responsible for outgrowth inhibition of Bacillus cereus spores was studied. Plantaricin JLA-9 had no detectable effects on germination initiation over 1 h on monitoring the hydration, heat resistance, and 2,6-pyridinedicarboxylic acid (DPA) release of spores. Rather, germination initiation is a prerequisite for the action of plantaricin JLA-9. Plantaricin JLA-9 inhibited growth by preventing the establishment of oxidative metabolism and disrupting membrane integrity in germinating spores within 2 h. The results suggest that plantaricin JLA-9 has potential applications in the control of Bacillus spp. in the food industry.

The objective of this study was to evaluate pathogenic and spoilage bacteria counts, physicochemical properties of fresh chilled pork treated with chitosan, nisin, and tea polyphenols along with their combination during storage at 4°C for 11 days. The result showed that treatments with chitosan, nisin, and tea polyphenols alone significantly (P < .05) reduced bacteria population (total viable counts (TVC), lactic acid bacteria, pseudomonas spp., staphylococcus spp., brochothrix thermosphacta, and enterobacteriaceae) on fresh chilled pork. The TVC of sample treated with a combination of nisin, tea polyphenols, and chitosan (N-TP-C) decreased from 7.2 to 5.95 log 10 CFU/g at 11th day. It was also found from TVB-N, TBARS, pH, color, waterholding capacity, and texture measurement that the N-TP-C combination treatment significantly maintained good quality and extended the shelf life of fresh chilled pork up to 11 days. In conclusion, it could be suggested that the combination with nisin, tea polyphenols, and chitosan has great potential to preserve fresh chilled pork.

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De®ning signals that can support the self-renewal of multipotential hemopoietic progenitor cells (MHPCs) is pertinent to understanding leukemogenesis and may be relevant to developing stem cell-based therapies.Here we de®ne a set of signals, JAK2 plus either c-kit or¯t-3, which together can support extensive MHPC self-renewal. Phenotypically and functionally distinct populations of MHPCs were obtained, depending on which receptor tyrosine kinase, c-kit or¯t-3, was activated. Self-renewal was abrogated in the absence of STAT5a/b, and in the presence of inhibitors targeting either the mitogen-activated protein kinase or phosphatidylinositol 3¢ kinase pathways. These ®nd-ings suggest that a simple two-component signal can drive MHPC self-renewal.