Chicken alpha-enolase but not beta-enolase has a Src-dependent tyrosine-phosphorylation site: cDNA cloning and nucleotide sequence analysis.
Chicken alpha- and beta-enolase cDNAs have been cloned and analyzed to reveal that alpha- but not beta-enolase has a Src-dependent phosphorylation site. The deduced amino acid sequence of the chicken alpha-enolase showed more than 90% homologies with those of other vertebrate alpha-enolases including amphibian (Xenopus laevis) alpha-like enolase. The chicken beta-enolase, on the other hand, shares 84-85% amino acid sequence homology with mammalian beta-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 alpha-enolase coincided with the reported tryptic peptide sequence of rabbit beta-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 alpha-enolase is the phosphorylation site by the tyrosine kinase. In chicken beta-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 beta-enolase was not phosphorylated in vivo or in vitro. Northern blot analysis indicated that alpha-enolase mRNA can be expressed in a wide range of chicken tissues, and that the gene expression switch from alpha to beta-enolase occurs just after hatching in developing chicken muscle.
Tanaka
M
M
Department of Biochemistry, Mie University Faculty of Medicine.
Maeda
K
K
Nakashima
K
K
D000595:Amino Acid Sequence; D000818:Animals; D001358:Avian Sarcoma Viruses / Q000201:enzymology*; D001483:Base Sequence; D002645:Chickens / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics*; D016391:Genes, src; D008969:Molecular Sequence Data; D010751:Phosphopyruvate Hydratase / Q000235:genetics*; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid
D018076:DNA, Complementary; D011505:Protein-Tyrosine Kinases; D010751:Phosphopyruvate Hydratase