Iron acquisition in Pasteurella haemolytica: expression and identification of a bovine-specific transferrin receptor

Abstract

Seven type 1 field isolates of Pasteurella haemolytica were screened for their ability to use different transferrins as a source of iron for growth. All seven strains were capable of using bovine but not human, porcine, avian, or equine transferrin. A screening assay failed to detect siderophore production in any of the strains tested. Iron-deficient cells from these strains expressed a binding activity, specific for bovine transferrin, that was regulated by the level of iron in the medium. Inhibition of expression by translation and transcription inhibitors suggested that iron regulation was occurring at the gene level. Affinity isolation of receptor proteins from all seven strains with biotinylated bovine transferrin identified a 100-kilodalton iron-regulated outer membrane protein as the bovine transferrin receptor. Iron-regulated outer membrane proteins of 71 and 77 kilodaltons were isolated along with the 100-kilodalton protein when less stringent washing procedures were employed in the affinity isolation procedure.

The region of human transferrin involved in binding to bacterial transferrin receptors is iocalized in the C‐lobe

“…1989;Sohryvers. 1989;Gonzaiez etaL, 1990; Ogunnariwo ef a/., 1990; Ogunnariwo and Schryvers, 1990). The receptors are characteristically specific for transferrin from the host species (Schryvers and Gonzalez.…”

“…the W-lobe fragment from the chymotrypsin digest (iane E) and the A/-iobe fragment from the trypsin digest (iane F) were used. Membranes from Pasteurella haemolytica grown under irondeficient conditions were used as a control (lane G) since the transferrin receptors from P. haemolytica are oniy specific for bovine transferrin (Ogunnariwo and Schryvers, 1990).…”

Iron supply of Pasteurella multocia and Pasteurella haemolotica

“…P. multocidu and P . hueri?o/~~tic:a are capable of using bovine transferrin by a specific receptor protein, that is regulated by the level of extracellular iron (OGUNNARIWO et a/. 1990(OGUNNARIWO et a/.…”

Neisseria meningitidis transferrin-binding protein 1 expressed in Escherichia coli is surface exposed and binds human transferrin

“…The expression of proteins by bacterial pathogens that can bind transferrin from their natural host, and in some cases the transferrin of other animals, has been described in N. meningitidis [1], N. gonorrhoeae [6], commensal Neisseria spp. [7], Haemophilus influenzae [8], Bordetella pertussis and B. bronchiseptica [17], Pasteurella haemolytica [18], and Actinobacillus pleuropneumoniae [9]. In general, two proteins, one of which is of variable molecular mass, bind transferrin and are expressed under conditions of iron-limitation.…”