Prokaryotic expression cloning of a novel human tyrosine kinase

Journal Article · Tue Feb 01 04:00:00 EST 1994 · Molecular and Cellular Biology

DOI:https://doi.org/10.1128/MCB.14.2.982· OSTI ID:577125

Beeler, J F; LaRochelle, W J; Chedid, M ^[1]

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1. National Cancer Inst., Bethesda, MD (United States); and others

Screening of a human embryonic lung fibroblast cDNA expression library with antiphosphotyrosine 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 predicted A6 protein lacked any of the motifs commonly conserved in the catalytic domains of protein kinases. However, 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. 29 refs., 8 figs., 1 tab.

• Sponsoring Organization: USDOE
• OSTI ID: 577125
• Journal Information: Molecular and Cellular Biology, Journal Name: Molecular and Cellular Biology Journal Issue: 2 Vol. 14; ISSN MCEBD4; ISSN 0270-7306
• Country of Publication: United States
• Language: English

Related Subjects

55 BIOLOGY AND MEDICINE
BASIC STUDIES
AMINO ACID SEQUENCE
ANTIBODIES
BIOLOGICAL EVOLUTION
CELL CYCLE
CELL PROLIFERATION
DNA SEQUENCING
DNA-CLONING
ENZYMES
FIBROBLASTS
GALACTOSIDASE
GENE REGULATION
GENES
MYELIN
NUCLEOTIDES
PHOSPHORYLATION
PHOSPHOTRANSFERASES
POLYMERASE CHAIN REACTION
SERINE
TRANSCRIPTION
TYROSINE