Galectin-1 (Gal-1) is important in immune function and muscle regeneration, but its expression and localization in adult tissues and primary leukocytes remain unclear. To address this, we generated a specific monoclonal antibody against Gal-1, termed αhGal-1, and defined a sequential peptide epitope that it recognizes, which is preserved in human and porcine Gal-1, but not in murine Gal-1. Using αhGal-1, we found that Gal-1 is expressed in a wide range of porcine tissues, including striated muscle, liver, lung, brain, kidney, spleen, and intestine. In most types of cells, Gal-1 exhibits diffuse cytosolic expression, but in cells within the splenic red pulp, Gal-1 showed both cytosolic and nuclear localization. Gal-1 was also expressed in arterial walls and exhibited prominent cytosolic and nuclear staining in cultured human endothelial cells. However, human peripheral leukocytes and promyelocytic HL60 cells lack detectable Gal-1 and also showed very low levels of Gal-1 mRNA. In striking contrast, Gal-1 exhibited an organized cytosolic staining pattern within striated muscle tissue of cardiac and skeletal muscle and colocalized with sarcomeric actin on I bands. These results provide insights into previously defined roles for Gal-1 in inflammation, immune regulation and muscle biology.

Chronic granulomatous disease (CGD) is a rare hereditary disorder characterized by recurrent life-threatening bacterial and fungal infections. The underlying defect in CGD is an inability of phagocytes to produce reactive oxygen species as a result of defects in NADPH oxidase. Considering that CGD generally affects about 3-4 in 1,000,000 individuals, it is surprising that the prevalence of CGD on Jeju Island is 20.7 in 1,000,000 individuals. We performed genetic analysis on 12 patients from 10 unrelated families and found that all patients had an identical homozygous single-base substitution of C to T in exon 1 (c.7C>T) of the CYBA gene, which was expected to result in a nonsense mutation (p.Q3X). Because Jeju Island has long been a geologically isolated region, the high prevalence of CGD on Jeju Island is presumably associated with an identical mutation inherited from a common ancestor or proband.

The ability of glycinecin A, a bacteriocin derived from Xanthomonas campestris pv. glycines 8ra, to kill closely related bacteria has been demonstrated previously by our group (S. G. Heu et al., Appl. Environ. Microbiol. 67:4105-4110, 2001). In the present study, we aimed at determining the glycinecin A-induced cause of death. Treatment with glycinecin A caused slow dissipation of membrane potential and rapid depletion of the pH gradient. Glycinecin A treatment also induced leakage of potassium ions from X. campestris pv. vesicatoria YK93-4 cells and killed sensitive bacterial cells in a dose-dependent manner. Sensitive cells were killed within 2 h of incubation, most likely due to the potassium ion efflux caused by glycinecin A. These results suggest that the bactericidal mechanism of action of glycinecin A is correlated with the permeability of membranes to hydroxyl and potassium ions, leading to the lethal activity of the bacteriocin on the target bacteria.

Glycinecin A, a bacteriocin produced by Xanthomonas campestris pv. glycines, inhibits the growth of X. campestris pv. vesicatoria. We have cloned and expressed the genes encoding glycinecin A in Escherichia coli. Recombinant glycinecin A was purified from cell extracts by ammonium sulfate precipitation followed by chromatography on Q-Sepharose, Mono Q (ion exchange), and size exclusion columns. Purified glycinecin A is composed of two polypeptides, is active over a wide pH range (6 to 9), and is stable at temperatures up to 60°C. Glycinecin A is a heterodimer consisting of 39- and 14-kDa subunits, as revealed through size exclusion chromatography and cross-linking analysis. Two genes, glyA and glyB, encoding the 39- and 14-kDa subunits, respectively, were identified based on the N-terminal sequences of the subunits. From the nucleotide sequences of glyA and glyB, we conclude that both genes are translated as bacteriocin precursors that include N-terminal leader sequences. When expressed in E. coli, recombinant glycinecin A was found primarily in cell extracts. In contrast, most glycinecin A from Xanthomonas was found in the culture media. E. coli transformed with either glyA or glyB separately did not show the bacteriocin activity.