title: A newly discovered human alpha-globin gene.
abstract: A previously undefined transcript with significant homology to the pseudo-alpha2 region of the alpha-globin locus on human chromosome 16 was detected as part of an effort to better define the transcriptional profiles of human reticulocytes. Cloning and sequencing of that transcript (GenBank AY698022; named mu-globin) revealed an insert with a 423-nucleotide open reading frame. BLASTP and ClustalW and phylogenetic analyses of 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 are largely conserved. Using quantitative real-time polymerase chain reaction (PCR), mu-globin was detected at a level of approximately 0.1% 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 suggest 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.
authors.affiliation: Molecular Medicine Branch, National Institute of Diabetes, Digestive and Kidney Disease, National Institutes of Health, Bldg 10/Rm 9B17, 10 Center Dr, Bethesda, MD 20892, USA.
authors.forename: Sung-Ho
authors.initials: SH
authors.lastname: Goh
authors.forename: Y Terry
authors.initials: YT
authors.lastname: Lee
authors.forename: Natarajan V
authors.initials: NV
authors.lastname: Bhanu
authors.forename: Margaret C
authors.initials: MC
authors.lastname: Cam
authors.forename: Richard
authors.initials: R
authors.lastname: Desper
authors.forename: Brian M
authors.initials: BM
authors.lastname: Martin
authors.forename: Ramy
authors.initials: R
authors.lastname: Moharram
authors.forename: Robert B
authors.initials: RB
authors.lastname: Gherman
authors.forename: Jeffery L
authors.initials: JL
authors.lastname: Miller
mesh_terms: D002454:Cell Differentiation / Q000235:genetics; D003001:Cloning, Molecular; D017124:Conserved Sequence; D004912:Erythrocytes / Q000737:chemistry; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D005914:Globins / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics*; D012156:Reticulocytes / Q000737:chemistry
chemical_list: D012333:RNA, Messenger; D005914:Globins