Chemotactically active proteins of neutrophils.

Polymorphonuclear leukocytes (neutrophils) are the first cells that arrive at sites of infection or injury. There, besides their microorganism-targeted effector functions, activated neutrophils secrete numerous chemoattractants that recruit other leukocyte subtypes into the inflamed tissue. First, neutrophil activation leads to the upregulation of the gene expression of several classical chemokines of the CXC and CC families. Second, neutrophil granules contain preformed intracellular storage pools of chemotactically active proteins that are rapidly released upon neutrophil degranulation. The third pathway of generation of chemotactically active proteins by activated neutrophils--shedding and concomitant proteolytic processing of a membrane protein--has recently been demonstrated in our laboratory. In this review, we summarize the essential features of chemoattractant production by neutrophils and their contribution to orchestrating the recruitment of leukocyte subtypes during inflammatory response.

Peptidyl-prolyl cis-trans isomerases: structure and functions.

Peptidyl-prolyl cis-trans isomerases (PPI) catalyze cis-trans isomerization of imide bonds in peptides and proteins. This review summarizes the literature on the structure and functions of PPIs, their involvement in protein folding, and organization of PPI-containing receptors and membrane channels. A possible role of several PPIs in distant interactions between cells is discussed.

Identification and localization of differences between Escherichia coli and Salmonella typhimurium genomes by suppressive subtractive hybridization.

The availability of bacterial genome sequences raises an important new problem - how can one move from completely sequenced microorganisms as a reference to the hundreds and thousands of other strains or isolates of the same or related species that will not be sequenced in the near future? An efficient way to approach this task is the comparison of genomes by subtractive hybridization. Recently we developed a sensitive and reproducible subtraction procedure for comparison of bacterial genomes, based on the method of suppression subtractive hybridization (SSH). In this work we demonstrate the applicability of subtractive hybridization to the comparison of the related but markedly divergent bacterial species Escherichia coli and Salmonella typhimurium. Clone libraries representing sequence differences were obtained and, in the case of completely sequenced E. coli genome, the differences were directly placed in the genome map. About 60% of the differential clones identified by SSH were present in one of the genomes under comparison and absent from the other. Additional differences in most cases represent sequences that have diverged considerably in the course of evolution. Such an approach to comparative bacterial genomics can be applied both to studies of interspecies evolution - to elucidate the "strategies" that enable different genomes to fit their ecological niches - and to development of diagnostic probes for the rapid identification of pathogenic bacterial species.