Nucleotide sequence analysis of human abl and bcr-abl cDNAs

Area of Science:

• Molecular Biology
• Genetics
• Biochemistry

Background:

• The abl gene is a proto-oncogene implicated in various cancers.
• Understanding the full sequence of abl RNA is crucial for comprehending its function and regulation.
• The bcr-abl fusion protein is a hallmark of chronic myeloid leukemia.

Purpose of the Study:

• To determine the complete nucleotide sequence of human abl RNA, including exon Ia.
• To analyze the structural and functional properties of the encoded abl protein.
• To investigate the role of the abl segment in bcr-abl constructs and their oncogenic potential.

Main Methods:

• Nucleotide sequencing of human abl RNA.
• Computer-aided protein structure prediction and analysis.
• Nucleotide analysis of bcr-abl cDNA from K562 cell line.
• Cell transformation assays using bcr-abl constructs and c-myc.

Main Results:

• The complete human abl RNA sequence spans 5598 nucleotides, encoding a 1130-amino acid protein.
• The 3' untranslated region contains regulatory elements and short open reading frames.
• Computer analysis predicted four distinct domains within the abl protein.
• The abl segment within a bcr-abl cDNA showed no coding region alterations.
• A bcr-abl construct with this abl segment transformed RAT-1 cells, yielding a highly active tyrosine kinase.

Conclusions:

• The determined sequence provides a comprehensive resource for studying human abl RNA and protein.
• The abl protein possesses distinct structural domains, suggesting complex functional roles.
• The abl segment contributes to the oncogenic potential of the bcr-abl fusion protein by generating a highly active tyrosine kinase.