Screening of a human embryonic lung fibroblast cDNA expression library with anti-phosphotyrosine antibodies led to isolation of a novel protein kinase. A clone. designated A6, contained a 3 kb cDNA insert with a predicted open reading frame of 350 amino acids. DNA sequence analysis failed to reveal any detectable similarity with previously known genes. and the predicated A6 protein lacked any of the motifs commonly conserved in the catalytic domains of protein kinases Yet. the bacterially expressed beta-galactosidase-A6 fusion protein demonstrated both tyrosine and serine phosphorylation in an in vitro kinase assay and phosphorylated exogenous substrates. including myelin basic protein specifically on tyrosine residues. The enzyme also displayed biochemical properties analogous to those of other protein tyrosine kinases. The A6 gene was found to be expressed widely at the transcript level in normal tissues and was evolutionarily conserved. Thus. A6 represents a novel tyrosine kinase which is highly divergent from previously described members of this important class of regulatory molecules.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Intramural Research (Z01)
Project #
1Z01CP005767-01
Application #
3752786
Study Section
Project Start
Project End
Budget Start
Budget End
Support Year
1
Fiscal Year
1994
Total Cost
Indirect Cost
Name
Division of Cancer Epidemiology and Genetics
Department
Type
DUNS #
City
State
Country
United States
Zip Code