Abstract

DEL CASTILLO, HERNANDO  and  VERNOT, JEAN PAUL. The primary structure of z chain in the Aotus nancymaae New World monkey. Caldasia [online]. 2008, vol.30, n.2, pp.325-336. ISSN 0366-5232.

The z chain is a transmembrane protein belonging to a multimeric complex in association with the T-cell receptor (TCR). The TCR is responsible for antigen recognition while the associated complex is responsible for signalling during activation. It has been shown that z chain expression becomes reduced in cancer and some autoimmune diseases. Tyrosine phosphorylation in immunoreceptor tyrosine-based activation motifs (ITAMs), present in the complex's different proteins is a critical event during activation. This report characterises the z chain in the new world monkey Aotus nancymaae; the amino acid sequence was deduced from its cDNA sequence. Aotus molecules revealed 95.5% and 95.7% identity with the human counterpart in nucleotide and amino acid sequences, respectively. Comparing different regions revealed 100% identity in the extra-cellular domain and conservation of important residues and domains in other regions of the protein: these included polar amino acids in the transmembrane region and the ITAMs. Our results suggest that the Aotus protein is fully functional and T-lymphocyte activation proceeds as in humans, supporting previous evidence that molecular structures involved in adaptive immune response are extremely conserved.

Keywords : Aotus nancymaae; adaptive immunity; z chain; associated complex; ITAMs.

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