Molecular characterisation of T cell receptor-zeta subunit (CD247) gene in buffalo (Bubalus bubalis)

Abstract

The cDNA encoding T cell receptor-zeta (TCR-ζ; CD247) molecule of water buffalo (Bubalus bubalis) was isolated, cloned and sequenced in the present study. The CD247 cDNA comprised 1078 nucleotides including a 30 nucleotide 5′-untranslated region (UTR), 495 nucleotide single open reading frame (ORF) and 553 nucleotide 3′-UTR. Deduced amino acid of buffalo CD247 sequence was two residues shorter than the corresponding cattle and sheep sequences. However, ruminant-specific insertions and substitutions in intra-cytoplasmic (IC) domain were present in buffalo. Immunoreceptor tyrosine-based activation motifs (ITAMs), the important motifs for TCR signalling, were totally conserved among ruminants including buffalo. The 3′-UTR region of the buffalo CD247 was highly homologous to the corresponding region in the cattle sequence and showed lack of polymorphism after polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis using HaeIII and MseI restriction enzymes in buffalo population. Phylogenetically, buffalo sequence was closer to cattle sequence under the ruminant's lineage. The conserved nature of this gene ensures TCR integrity which is vital for induction of optimal and efficient immune response.