This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Aebi, C. Articles by Hansen, E. J. Search for Related Content PubMed PubMed Citation Articles by Aebi, C. Articles by Hansen, E. J.

 Previous Article  |  Next Article 

Infect. Immun., 06 1996, 2024-2030, Vol 64, No. 6
Copyright © 1996, American Society for Microbiology

Expression of the CopB outer membrane protein by Moraxella catarrhalis is regulated by iron and affects iron acquisition from transferrin and lactoferrin

C Aebi, B Stone, M Beucher, LD Cope, I Maciver, SE Thomas, GH McCracken Jr, PF Sparling and EJ Hansen
Department of Microbiology, University of Texas Southwestern Medical Center, Dallas 75235, USA.

The amino acid sequence of the cell-surface-exposed, 81-kDa CopB outer membrane protein of Moraxella catarrhalis was found to be similar to those of TonB-dependent outer membrane proteins of other gram-negative bacteria. Expression of CopB was affected by the availability of iron in the growth medium, and the extent of overexpression of CopB in response to iron limitation varied widely among the M. catarrhalis strains tested. Wild-type M. catarrhalis strains were found to be able to utilize ferric citrate, transferrin, lactoferrin, and heme as sources of iron for growth in vitro. However, an isogenic copB mutant was severely impaired in its ability to utilize transferrin and lactoferrin as sole sources of iron for growth, whereas this same mutant grew similarly to the wild-type parent strain when supplied with ferric citrate as the iron source. The copB mutant was not significantly different from its wild-type parent strain in its ability to bind transferrin and lactoferrin. In addition, the wild-type parent strain and the copB mutant exhibited equivalent rates of uptake of 55Fe from ferric citrate. However, the copB mutant was markedly less able than the wild-type strain to take up 55Fe from transferrin and lactoferrin. These results indicate that lack of expression of the CopB protein exerts a direct or indirect effect on the ability of M. catarrhalis to utilize iron bound to certain carrier proteins.

This article has been cited by other articles:

• Attia, A. S., Sedillo, J. L., Wang, W., Liu, W., Brautigam, C. A., Winkler, W., Hansen, E. J. (2008). Moraxella catarrhalis Expresses an Unusual Hfq Protein. Infect. Immun. 76: 2520-2530 [Abstract] [Full Text]  
• Wang, W., Reitzer, L., Rasko, D. A., Pearson, M. M., Blick, R. J., Laurence, C., Hansen, E. J. (2007). Metabolic Analysis of Moraxella catarrhalis and the Effect of Selected In Vitro Growth Conditions on Global Gene Expression. Infect. Immun. 75: 4959-4971 [Abstract] [Full Text]  
• Easton, D. M., Smith, A., Gallego, S. G., Foxwell, A. R., Cripps, A. W., Kyd, J. M. (2005). Characterization of a Novel Porin Protein from Moraxella catarrhalis and Identification of an Immunodominant Surface Loop. J. Bacteriol. 187: 6528-6535 [Abstract] [Full Text]  
• Furano, K., Luke, N. R., Howlett, A. J., Campagnari, A. A. (2005). Identification of a conserved Moraxella catarrhalis haemoglobin-utilization protein, MhuA. Microbiology 151: 1151-1158 [Abstract] [Full Text]  
• Nordstrom, T., Blom, A. M., Forsgren, A., Riesbeck, K. (2004). The Emerging Pathogen Moraxella catarrhalis Interacts with Complement Inhibitor C4b Binding Protein through Ubiquitous Surface Proteins A1 and A2. J. Immunol. 173: 4598-4606 [Abstract] [Full Text]  
• Holm, M. M., Vanlerberg, S. L., Foley, I. M., Sledjeski, D. D., Lafontaine, E. R. (2004). The Moraxella catarrhalis Porin-Like Outer Membrane Protein CD Is an Adhesin for Human Lung Cells. Infect. Immun. 72: 1906-1913 [Abstract] [Full Text]  
• Stutzmann Meier, P., Heiniger, N., Troller, R., Aebi, C. (2003). Salivary Antibodies Directed against Outer Membrane Proteins of Moraxella catarrhalis in Healthy Adults. Infect. Immun. 71: 6793-6798 [Abstract] [Full Text]  
• Mollenkvist, A., Nordstrom, T., Hallden, C., Christensen, J. J., Forsgren, A., Riesbeck, K. (2003). The Moraxella catarrhalis Immunoglobulin D-Binding Protein MID Has Conserved Sequences and Is Regulated by a Mechanism Corresponding to Phase Variation. J. Bacteriol. 185: 2285-2295 [Abstract] [Full Text]  
• Verduin, C. M., Hol, C., Fleer, A., van Dijk, H., van Belkum, A. (2002). Moraxella catarrhalis: from Emerging to Established Pathogen. Clin. Microbiol. Rev. 15: 125-144 [Abstract] [Full Text]  
• Sethi, S., Murphy, T. F. (2001). Bacterial Infection in Chronic Obstructive Pulmonary Disease in 2000: a State-of-the-Art Review. Clin. Microbiol. Rev. 14: 336-363 [Abstract] [Full Text]  
• Lafontaine, E. R., Wagner, N. J., Hansen, E. J. (2001). Expression of the Moraxella catarrhalis UspA1 Protein Undergoes Phase Variation and Is Regulated at the Transcriptional Level. J. Bacteriol. 183: 1540-1551 [Abstract] [Full Text]  
• Lafontaine, E. R., Cope, L. D., Aebi, C., Latimer, J. L., McCracken, G. H. Jr., Hansen, E. J. (2000). The UspA1 Protein and a Second Type of UspA2 Protein Mediate Adherence of Moraxella catarrhalis to Human Epithelial Cells In Vitro. J. Bacteriol. 182: 1364-1373 [Abstract] [Full Text]  
• Yu, R.-h., Bonnah, R. A., Ainsworth, S., Schryvers, A. B. (1999). Analysis of the Immunological Responses to Transferrin and Lactoferrin Receptor Proteins from Moraxella catarrhalis. Infect. Immun. 67: 3793-3799 [Abstract] [Full Text]  
• Cope, L. D., Lafontaine, E. R., Slaughter, C. A., Hasemann, C. A. Jr., Aebi, C., Henderson, F. W., McCracken, G. H. Jr., Hansen, E. J. (1999). Characterization of the Moraxella catarrhalis uspA1 and uspA2 Genes and Their Encoded Products. J. Bacteriol. 181: 4026-4034 [Abstract] [Full Text]  
• Carson, S. D. B., Klebba, P. E., Newton, S. M. C., Sparling, P. F. (1999). Ferric Enterobactin Binding and Utilization by Neisseria gonorrhoeae. J. Bacteriol. 181: 2895-2901 [Abstract] [Full Text]  
• Bonnah, R. A., Wong, H., Loosmore, S. M., Schryvers, A. B. (1999). Characterization of Moraxella (Branhamella) catarrhalis lbpB, lbpA, and Lactoferrin Receptor orf3 Isogenic Mutants. Infect. Immun. 67: 1517-1520 [Abstract] [Full Text]  
• Aebi, C., Lafontaine, E. R., Cope, L. D., Latimer, J. L., Lumbley, S. L., McCracken, G. H. Jr., Hansen, E. J. (1998). Phenotypic Effect of Isogenic uspA1 and uspA2 Mutations on Moraxella catarrhalis 035E. Infect. Immun. 66: 3113-3119 [Abstract] [Full Text]  
• Bonnah, R. A., Schryvers, A. B. (1998). . J. Bacteriol. 180: 3080-3090 [Abstract] [Full Text]  
• Aebi, C., Cope, L. D., Latimer, J. L., Thomas, S. E., Slaughter, C. A., McCracken, G. H. Jr., Hansen, E. J. (1998). Mapping of a Protective Epitope of the CopB Outer Membrane Protein of Moraxella catarrhalis. Infect. Immun. 66: 540-548 [Abstract] [Full Text]  
• Elkins, C., Totten, P. A., Olsen, B., Thomas, C. E. (1998). Role of the Haemophilus ducreyi Ton System in Internalization of Heme from Hemoglobin. Infect. Immun. 66: 151-160 [Abstract] [Full Text]