This Article Full Text 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 Kunchithapautham, K. Articles by Scott, A. L. Search for Related Content PubMed PubMed Citation Articles by Kunchithapautham, K. Articles by Scott, A. L.

 Previous Article  |  Next Article 

Infection and Immunity, July 2003, p. 4119-4126, Vol. 71, No. 7
0019-9567/03/$08.00+0     DOI: 10.1128/IAI.71.7.4119-4126.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.

Thioredoxin from Brugia malayi: Defining a 16-Kilodalton Class of Thioredoxins from Nematodes

Kannan Kunchithapautham,¹ B. Padmavathi,¹ R. B. Narayanan,¹ P. Kaliraj,¹ and Alan L. Scott^2*

Centre for Biotechnology, Anna University, Chennai, India,¹ W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland 21205²

Received 16 December 2002/ Returned for modification 7 February 2003/ Accepted 28 February 2003

Thioredoxins are a family of small redox proteins that undergo NADPH-dependent reduction by thioredoxin reductase. This results in a supply of reducing equivalents that cells use in a wide variety of biological reactions, which include maintaining reduced forms of the enzymes important for protection against damage from high-energy oxygen radicals, the regulation of transcription factor activity, and the inhibition of apoptosis. Here we report on a new member of the thioredoxin family of proteins from the filarial nematode Brugia malayi, Bm-TRX-1, which defines a new subclass of 16-kDa thioredoxins that occur widely in nematodes, including Caenorhabditis elegans. In addition to being larger than the thioredoxins found in mammalian and bacterial species, the putative active site sequence of Bm-TRX-1, WCPPC, does not conform to the highly conserved WCGPC reported for thioredoxins from mammals to bacteria. Interestingly, an allelic form of Bm-TRX-1 was identified with an active site sequence WCPQC, which appears to be unique to the thioredoxins from filarial species. Bm-TRX-1 was between 98% and 35% identical to thioredoxins from other nematodes and 20% identical to the thioredoxins from mammals and Escherichia coli. Bm-TRX-1 was constitutively transcribed throughout the B. malayi life cycle, and Bm-TRX protein was detectable in somatic extracts and excretory-secretory products from adults and microfilariae. Recombinant Bm-TRX-1 had thiodisulfide reductase activity, as measured by the reduction of insulin, and protected DNA from the nicking activity of oxygen radicals. Overexpression of Bm-TRX-1 in a human monocyte cell line negatively regulated tumor necrosis factor alpha-induced p38 mitogen-activated protein kinase activity, suggesting a possible role of the 16-kDa Bm-TRX-1 in immunomodulation.

---

* Corresponding author. Mailing address: W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, 615 North Wolfe Street, Baltimore, MD 21205. Phone: (410) 955-3430. Fax: (410) 955-0105. E-mail: ascott{at}jhsph.edu.

Editor: J. M. Mansfield

---

Infection and Immunity, July 2003, p. 4119-4126, Vol. 71, No. 7
0019-9567/03/$08.00+0     DOI: 10.1128/IAI.71.7.4119-4126.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.

This article has been cited by other articles:

• Jee, C., Vanoaica, L., Lee, J., Park, B. J., Ahnn, J. (2005). Thioredoxin is related to life span regulation and oxidative stress response in Caenorhabditis elegans. GENES CELLS 10: 1203-1210 [Abstract] [Full Text]