Disease relevance of hlyC

• HlyC was not detected by Western blot in an E. coli strain encoding hlyC and hlyA, but it was present in a strain encoding only hlyC [1].
• Identification of a major cluster including 96.4% of the strains carrying the cnf1, papC, and hlyC genes and ECOR subgroup B2 strains suggested that the virulent E. coli strains causing bacteremia in cancer patients are closely related to ECOR B2 strains [2].
• Nonreciprocal complementation of the hlyC and lktC genes of the Escherichia coli hemolysin and Pasteurella haemolytica leukotoxin determinants [3].
• In these studies, the Bordetella pertussis adenylate cyclase toxin-hemolysin homology to the Escherichia coli hemolysin is extended with the finding of cyaC, a homolog to the E. coli hlyC gene, which is required for the production of a functional hemolysin molecule in E. coli [4].

High impact information on hlyC

• We did not detect HlyC in cell lysates from hlyC mutants with different abilities to acylate pro-HlyA, suggesting that the degradation of HlyC is not related to the HlyA acylation process [1].
• Export of the intracellular A. pleuropneumoniae prohaemolysin out into the medium was achieved by the presence in trans of the E. coli haemolysin secretion genes hlyB and hlyD, and high levels of intracellular haemolytic activity were attained similarly by the E. coli post-translational haemolysin activator gene, hlyC [5].
• To investigate this hypothesis, we compared the frequency of the virulence-related genes cnf1, cnf2, papC, hlyC, and iut in 155 E. coli strains isolated from hospitalized cancer patients with epidemiologically unrelated cases of bacteremia to their frequency in 70 E. coli strains isolated from the feces of healthy unrelated volunteers [2].
• When hlyC was provided in trans to lktA, the toxin that was produced had the same activity and target cell specificity as the wild-type leukotoxin; it was leukotoxic for bovine lymphoid cells but not human lymphoblast cells when it was evaluated by a 51Cr-release assay [3].
• Here we demonstrated that E. coli carrying the cloned enterohemolysin operon (hlyC, A, B, D genes) from an STEC human strain induced the production of interleukin-1beta (IL-1beta) through its mRNA expression but not tumor necrosis factor-alpha from human monocytes [6].

Biological context of hlyC

• The inserts were further subcloned either as SalI fragments in pACYC184 or as BamHI-SalI fragments in a recombinant plasmid (pANN202) containing cistron C (hlyC) of the plasmid-encoded hemolysin determinant [7].
• In this paper the DNA sequence of the cloned hlyC gene from E. coli 2001 is presented [8].
• Deletion analysis of pSF4000 combined with quantification of the hemolysin structural protein HlyA by immunoblotting confirmed that major control of HlyA expression occurs within a 168-base-pair PstI fragment located 433 base pairs upstream of the start of hlyC [9].
• Sequence analysis of the upstream region defined an open reading frame with homology to the E. coli hlyC gene [4].
• The activity of beta-galactosidase is considerably lower when Mud-1 is integrated in hlyBa than when it is inserted in hlyC, suggesting a considerable decline in hly gene expression from hlyC to hlyBa [10].

Anatomical context of hlyC

• The fusion proteins HlyC-beta-gal and HlyA-beta-gal were predominantly detected in the cytoplasm, confirming previous data which suggested that the primary gene products of hlyC and hlyA are not transported across the cytoplasmic membrane [11].
• This activity was found in the periplasm; very little hemolysin activity was found in the cytoplasm, suggesting that the hlyC product is required for transport or activation of the hlyA product or both [12].

References