HGNC Approved Gene Symbol:HBM
Cytogenetic location:16p13.3 Genomic coordinates(GRCh38) :16:165,978-166,764 (from NCBI)
Using postgenomic approaches to examine the transcriptional profiles of human reticulocytes,Goh et al. (2005) characterized a previously undefined transcript representing an unrecognized globin gene that showed homology to the pseudo-HbA2 region within the alpha-globin locus (see141800) on chromosome 16p13.3. Cloning and sequencing of that transcript, named hemoglobin (Hb) mu (HBM), revealed an insert with a 423-nucleotide open reading frame. The predicted protein demonstrated a high level of homology with the avian alpha-D globin. In addition, the heme- and globin-binding amino acids of mu-globin and avian alpha-D globin were largely conserved. Using quantitative real-time PCR, mu-globin was detected at a level of approximately 0.1% of that measured for alpha-globin in erythroid tissues. Erythroid-specific expression was detected by Northern blot analysis, and maximal expression during the erythroblast terminal differentiation was also detected. Despite this highly regulated pattern of mu-globin gene transcription, mu-globin protein was not detected by mass spectrometry. These results suggested that the human genome encodes a previously unrecognized globin member of the avian alpha-D family that is transcribed in a highly regulated pattern in erythroid cells.
Goh et al. (2005) commented that it is curious that mu-globin is not the only gene in the human alpha-globin cluster that lacks a detectable hemoglobin product. The downstream region of the alpha locus contains an unusual gene named theta-globin (HbQ1;142240) that generates no detected globin protein in humans. Theta-globin gene transcription is regulated, and the transcripts contain no obvious defects to explain the lack of detectable protein in erythroid tissues. Both the HBM and HbQ1 genes are well conserved at the genomic level, and both have a highly regulated pattern of transcription in erythroid cells. It was uncertain whether the HBM gene is evolving toward becoming a pseudogene;Goh et al. (2005) raised the possibility that instead, this ancient globin has a function for which high-level protein expression is not required.
Goh et al. (2005) determined that the HBM gene has a 3-exon structure similar to that of other human hemoglobin alpha genes.
The HBM gene maps to the alpha-globin region on chromosome 16p13.3, overlapping the pseudo-Hb2 gene (Goh et al., 2005).
Goh, S.-H., Lee, Y. T., Bhanu, N. V., Cam, M. C., Desper, R., Martin, B. M., Moharram, R., Gherman, R. B., Miller, J. L.A newly discovered human alpha-globin gene. Blood 106: 1466-1472, 2005. [PubMed:15855277,images,related citations] [Full Text]
Alternative titles; symbols
HGNC Approved Gene Symbol: HBM
Cytogenetic location: 16p13.3 Genomic coordinates(GRCh38) : 16:165,978-166,764(from NCBI)
Using postgenomic approaches to examine the transcriptional profiles of human reticulocytes, Goh et al. (2005) characterized a previously undefined transcript representing an unrecognized globin gene that showed homology to the pseudo-HbA2 region within the alpha-globin locus (see 141800) on chromosome 16p13.3. Cloning and sequencing of that transcript, named hemoglobin (Hb) mu (HBM), revealed an insert with a 423-nucleotide open reading frame. The predicted protein demonstrated a high level of homology with the avian alpha-D globin. In addition, the heme- and globin-binding amino acids of mu-globin and avian alpha-D globin were largely conserved. Using quantitative real-time PCR, mu-globin was detected at a level of approximately 0.1% of that measured for alpha-globin in erythroid tissues. Erythroid-specific expression was detected by Northern blot analysis, and maximal expression during the erythroblast terminal differentiation was also detected. Despite this highly regulated pattern of mu-globin gene transcription, mu-globin protein was not detected by mass spectrometry. These results suggested that the human genome encodes a previously unrecognized globin member of the avian alpha-D family that is transcribed in a highly regulated pattern in erythroid cells.
Goh et al. (2005) commented that it is curious that mu-globin is not the only gene in the human alpha-globin cluster that lacks a detectable hemoglobin product. The downstream region of the alpha locus contains an unusual gene named theta-globin (HbQ1; 142240) that generates no detected globin protein in humans. Theta-globin gene transcription is regulated, and the transcripts contain no obvious defects to explain the lack of detectable protein in erythroid tissues. Both the HBM and HbQ1 genes are well conserved at the genomic level, and both have a highly regulated pattern of transcription in erythroid cells. It was uncertain whether the HBM gene is evolving toward becoming a pseudogene; Goh et al. (2005) raised the possibility that instead, this ancient globin has a function for which high-level protein expression is not required.
Goh et al. (2005) determined that the HBM gene has a 3-exon structure similar to that of other human hemoglobin alpha genes.
The HBM gene maps to the alpha-globin region on chromosome 16p13.3, overlapping the pseudo-Hb2 gene (Goh et al., 2005).
Goh, S.-H., Lee, Y. T., Bhanu, N. V., Cam, M. C., Desper, R., Martin, B. M., Moharram, R., Gherman, R. B., Miller, J. L.A newly discovered human alpha-globin gene. Blood 106: 1466-1472, 2005. [PubMed: 15855277] [Full Text: https://doi.org/10.1182/blood-2005-03-0948]
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