Original Article

Genes and Immunity (2003) 4, 298–311. doi:10.1038/sj.gene.6363949

Identification, structural characterization, and tissue distribution of Tsg-5: a new TNF-stimulated gene

E F Abrantes1,2, E G Pires3, A F Carvalho1, F F Costa1,3, W Savino4 and L F L Reis1,3

  1. 1Ludwig Institute for Cancer Research, São Paulo. Brazil
  2. 2Department of Biochemistry and Immunology, UFMG, Belo Horizonte, Brazil
  3. 3Centro de Tratamento e Pesquisa Hospital do Câncer, São Paulo, Brazil
  4. 4Department of Immunology, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil

Correspondence: Dr LFL Reis, Rua Prof. Antônio Prudente 109, 4th floor, São Paulo, SP, 01509-010, Brazil. E-mail: lreis@ludwig.org.br

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Abstract

Using DDRT-PCR, we compared the mRNA content of untreated and TNF-treated mouse embryonic fibroblasts (MEFs). Among differentially represented fragments, we identified and cloned a novel TNF-stimulated gene named Tsg-5. This gene, mapped to mouse chromosome 14, has three exons that can be alternatively spliced giving rise to two mRNA species, one spanning three exons and another that skips the second exon. Analysis of full-length Tsg-5 cDNA revealed a potential start codon within exon 2 encoding an ORF of 40 amino-acids. No homology with known mouse or human sequences, neither at the nucleotide nor at the amino-acid level could be found in public databases. In MEFs, Tsg-5 is induced by tumor necrossis factor-alpha (TNF) and IL-1beta, albeit with distinct kinetics. TNF-induced Tsg-5 expression is NF-kappaB-dependent as it was inhibited by MG132, lactacystin, Bay 11–7083, and Bay 11–7085. Analysis of Tsg-5 expression in vivo revealed that the gene and its encoded polypeptide are constitutively expressed in the thymus and ovary, whereas, in LPS-treated mice, Tsg-5 mRNA can be detected in the spleen, lung, and brain. Our data suggest that Tsg-5 encodes a new, rare transcript, with a very tight regulation of expression and differential splicing.

Keywords:

TNF, NF-kappaB, differential display, thymus, ovary, inflammation