Chicken α-Enolase but Not β-Enolase Has a Src-Dependent Tyrosine-Phosphorylation Site: cDNA Cloning and Nucleotide Sequence Analysis

• Published in: Journal of biochemistry (Tokyo) 1995-03, Vol.117 (3), p.554-559
• Main Authors: Tanaka, Minoru, Maeda, Kayoko, Nakashima, Kunio
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Avian Sarcoma Viruses - enzymology; Base Sequence; cDNA cloning; chicken α-enolase; chicken β-enolase; Chickens - genetics; Chickens - metabolism; Cloning, Molecular; DNA, Complementary - genetics; gene expression; Genes, src; Molecular Sequence Data; Phosphopyruvate Hydratase - genetics; Phosphorylation; Protein-Tyrosine Kinases - metabolism; Sequence Homology, Amino Acid; tyrosine phosphorylation site
• ISSN: 0021-924X
• DOI: 10.1093/oxfordjournals.jbchem.a124743

Chicken α- and β-enolase cDNAs have been cloned and analyzed to reveal that α- but not β-enolase has a Src-dependent phosphorylation site. The deduced amino acid sequence of the chicken α-enolase showed more than 90% homologies with those of other vertebrate α-enolases including amphibian (Xenopus laevis) α-like enolase. The chicken β-enolase, on the other hand, shares 84–85% amino acid sequence homology with mammalian β-enolases. These chicken enolases also showed more than 70% sequence identity with an insect (Drosophila melanogaster) enolase and around 60% with two yeast enolases. The amino acid sequence between residues 33 and 50 in chicken α-enolase coincided with the reported tryptic peptide sequence of rabbit β-enolase, the tyrosine residue in which was phosphorylated in vitro by Rous-sarcoma-virus tyrosine kinase. The present finding suggested that the tyrosine residue at position 44 in chicken α-enolase is the phosphorylation site by the tyrosine kinase. In chicken β-enolase, on the other hand, the corresponding tyrosine residue was found to be replaced with a histidine residue, in accordance with the previous observation that chicken β-enolase was not phosphorylated in vivo or in vitro. Northern blot analysis indicated that α-enolase mRNA can be expressed in a wide range of chicken tissues, and that the gene expression switch from α- to β-enolase occurs just after hatching in developing chicken muscle.