Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 1432-1211
    Keywords: Key words J chain ; Polymeric immunoglobulin ; Ontogeny ; Evolution ; Comparative immunology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The J chain is a component of polymeric immunoglobulin (Ig) molecules and may play an important role in their polymerization and the transport of polymeric Ig across epithelial cells. In this study, the primary structure of the chicken J chain was determined by sequencing cDNA clones. The cDNA had an open reading frame of 476 nucleotides encoding a putative protein of 158 amino acid residues including the signal sequence. The 3′ untranslated region consisted of 1216 nucleotides and a poly(A) tail. The deduced amino acid sequence of the chicken J chain had a high degree of homology to that of human, cow, rabbit, mouse, frog, and earthworm, with eight conserved Cys residues identical to the mammalian J chains. Northern blot hybridization performed with total RNA from various chicken tissues revealed high levels of J-chain mRNA expression in spleen, intestine, Harderian gland, and bursa of Fabricius, and low levels in the thymus. The J chain was expressed in the bursa as early as day 15 of embryogenesis. These data indicated that the chicken J-chain gene displays a high degree of homology with that of other species, and is expressed at an early stage of development of the chicken immune system.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-1211
    Keywords: Key words Human ; Mucosa ; Gene regulation ; Cytokines ; Transcription factors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  We analyzed the mechanism of human polymeric immunoglobulin receptor (pIgR) gene upregulation by tumor necrosis factor (TNF)-α. Northern blot analysis showed that the expression of pIgR mRNA was enhanced by TNF-α stimulation. This activation was completely inhibited by RNA polymerase or protein synthesis inhibitors, suggesting that the regulation of pIgR gene expression depends on de novo RNA and protein synthesis. Furthermore, the stimulation of pIgR mRNA by TNF-α was decreased by pyrrolidinedithiocarbamate and l-1-4′-tosylamino-phenylethyl-chloromethyl ketone, which are known nuclear factor (NF)-κB inhibitors. For further analysis of gene regulation, we cloned and sequenced the 1.5-kb 5′-flanking region of the pIgR gene. In the upstream region, we found two NF-κB-binding motifs (named κB1 and κB2 from the 5′ region). An electrophoretic mobility shift assay indicated that two components of the NF-κB/Rel family, p50 and p65, bound with higher affinity to the κB2 element than to the κB1 element. We also analyzed pIgR gene expression using reporter plasmids expressing the firefly luciferase gene. Stimulation by TNF-α significantly activated the pIgR gene promoter, as a 775-bp upstream region of the pIgR gene increased luciferase gene expression in cells treated with TNF-α. The activation of promoter activity by TNF-α was abolished when a mutation was inserted into κB1 or κB2. These data indicated that pIgR gene expression induced by TNF-α is transcriptionally regulated via activation of NF-κB. In addition, there is a possibility that another factor may act in concert with NF-κB.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...