Human Myeloperoxidase Gene Research Articles

Chromosomal gene structure of human myeloperoxidase and regulation of its expression by granulocyte colony-stimulating factor.

By using the full-length cDNA as a probe, the chromosomal gene for human myeloperoxidase was isolated from a human gene library. Comparison of the nucleotide sequence of the chromosomal gene with that of the cDNA has revealed that the human myeloperoxidase gene is composed of 12 exons and 11 introns. S1 mapping analysis of human myeloperoxidase mRNA identified the single transcription initiation site at 180 base pairs upstream of the ATG initiation codon. In the 5'-flanking region of the human myeloperoxidase gene, there are several blocks of sequences which are homologous to the sequences found on the 5'-promoter region of the human c-myc proto-oncogene. The myeloperoxidase gene is expressed in mouse myeloid leukemia WEHI-3B D+ and NFS-60 cells. When these cells were treated with human recombinant granulocyte colony-stimulating factor, the steady-state level of myeloperoxidase mRNA declined to zero within 36 h in WEHI-3B D+ cells, but not in NFS-60 cells.

Human Myeloperoxidase Gene: Molecular Cloning and Expression in Leukemic Cells

We have molecularly cloned the human myeloperoxidase (MPO) gene from the lambda gt11 expression library by screening with an affinity-purified MPO antibody. The cDNA clone of the MPO gene was used to study MPO gene expression in leukemic cells. The amino acid sequence predicted from the nucleotide sequence of the cDNA clone pMP401 matched exactly the 23 amino acid sequence of the NH2-terminal of the 60,000 MPO subunit. We found that MPO cDNA hybridized to a single EcoRI genomic band of 19 kb, indicating that the MPO gene represents a single gene in the human genome. Northern blot analysis of RNA isolated from leukemic cell lines and acute myelogenous leukemia (AML) patients' samples shows that MPO gene expression correlated with myeloid lineage. The intensity of MPO mRNA expression on Northern blot correlated with the level of MPO expression by cytochemical staining. Multiple species of MPO mRNA were found. This indicates that a single MPO gene may encode different RNA species through a mechanism of posttranscriptional processing or that multiple transcriptional start/termination sites exist in the MPO gene.

Human myeloperoxidase gene: molecular cloning and expression in leukemic cells

We have molecularly cloned the human myeloperoxidase (MPO) gene from the lambda gt11 expression library by screening with an affinity- purified MPO antibody. The cDNA clone of the MPO gene was used to study MPO gene expression in leukemic cells. The amino acid sequence predicted from the nucleotide sequence of the cDNA clone pMP401 matched exactly the 23 amino acid sequence of the NH2-terminal of the 60,000 MPO subunit. We found that MPO cDNA hybridized to a single EcoRI genomic band of 19 kb, indicating that the MPO gene represents a single gene in the human genome. Northern blot analysis of RNA isolated from leukemic cell lines and acute myelogenous leukemia (AML) patients' samples shows that MPO gene expression correlated with myeloid lineage. The intensity of MPO mRNA expression on Northern blot correlated with the level of MPO expression by cytochemical staining. Multiple species of MPO mRNA were found. This indicates that a single MPO gene may encode different RNA species through a mechanism of posttranscriptional processing or that multiple transcriptional start/termination sites exist in the MPO gene.