Isolation and characterization of the cDNA encoding human DNA methyltransferase

Area of Science:

• Molecular Biology
• Genetics
• Biochemistry

Background:

• DNA methyltransferase (DNA MTase) is crucial for establishing DNA methylation patterns.
• Understanding human DNA MTase is essential for studying gene regulation and diseases like cancer.

Purpose of the Study:

• To clone and characterize the human DNA methyltransferase (DNA MTase) cDNA.
• To investigate the structural and functional similarities between human and mouse DNA MTase.
• To determine the genomic location and expression patterns of human DNA MTase.

Main Methods:

• cDNA cloning and sequencing
• Homology analysis with mouse DNA MTase
• Northern blot analysis for tissue expression
• Fluorescence in situ hybridization (FISH) for gene localization

Main Results:

• Cloned a 5194 bp human DNA MTase cDNA encoding a 1495 amino acid protein.
• Human DNA MTase shares 80% nucleotide and 74% amino acid homology with mouse DNA MTase.
• Conserved motifs, including a catalytic site, are present in the human protein.
• A single 5.2 kb transcript is expressed in all human tissues, with highest levels in placenta, brain, heart, and lung.
• The human DNA MTase gene is localized to chromosome 19p13.2-p13.3.

Conclusions:

• The human DNA MTase cDNA has been isolated and characterized.
• Structural similarities suggest conserved function between human and mouse DNA MTase.
• The gene's localization and expression patterns provide a basis for further functional studies.
• This research facilitates future investigations into DNA MTase regulation and its role in normal and neoplastic cells.