HBG1
Hemoglobin subunit gamma-1 is a protein that in humans is encoded by the HBG1 gene.[2]
Function
The gamma globin genes (HBG1 and HBG2) are normally expressed in the fetal liver, spleen and bone marrow. Two gamma chains together with two alpha chains constitute fetal hemoglobin (HbF) which is normally replaced by adult hemoglobin (HbA) in the year following birth. In the non-pathological condition known as hereditary persistence of fetal hemoglobin (HPFH), gamma globin expression is continued into adulthood. Also, in cases of beta-thalassemia and related conditions, gamma chain production may be maintained, possibly as a mechanism to compensate for the mutated beta-globin. The two types of gamma chains differ at residue 136 where glycine is found in the G-gamma product (HBG2) and alanine is found in the A-gamma product (HBG1). The former is predominant at birth. The order of the genes in the beta-globin cluster is: 5' - epsilon – gamma-G – gamma-A – delta – beta - 3'.[3]
References
Further reading
- Huisman TH, Kutlar F, Gu LH (1992). "Gamma chain abnormalities and gamma-globin gene rearrangements in newborn babies of various populations.". Hemoglobin. 15 (5): 349–79. doi:10.3109/03630269108998857. PMID 1802881.
- Gelinas R, Yagi M, Endlich B, et al. (1985). "Sequences of G gamma, A gamma, and beta genes of the Greek (A gamma) HPFH mutant: evidence for a distal CCAAT box mutation in the A gamma gene.". Prog. Clin. Biol. Res. 191: 125–39. PMID 2413469.
- Giardina B, Messana I, Scatena R, Castagnola M (1995). "The multiple functions of hemoglobin.". Crit. Rev. Biochem. Mol. Biol. 30 (3): 165–96. doi:10.3109/10409239509085142. PMID 7555018.
- Anderson NL, Anderson NG (2003). "The human plasma proteome: history, character, and diagnostic prospects.". Mol. Cell Proteomics. 1 (11): 845–67. doi:10.1074/mcp.R200007-MCP200. PMID 12488461.
- Chang JC, Kan YW (1979). "beta 0 thalassemia, a nonsense mutation in man". Proc. Natl. Acad. Sci. U.S.A. 76 (6): 2886–9. doi:10.1073/pnas.76.6.2886. PMC 383714. PMID 88735.
- Saglio G, Ricco G, Mazza U, et al. (1979). "Human T gamma globin chain is a variant of A gamma chain (A gamma Sardinia)". Proc. Natl. Acad. Sci. U.S.A. 76 (7): 3420–4. doi:10.1073/pnas.76.7.3420. PMC 383837. PMID 291015.
- Poon R, Kan YW, Boyer HW (1979). "Sequence of the 3'-noncoding and adjacent coding regions of human gamma-globin mRNA". Nucleic Acids Res. 5 (12): 4625–30. PMC 342777. PMID 318163.
- Grifoni V, Kamuzora H, Lehmann H, Charlesworth D (1975). "A new Hb variant: Hb F Sardinia gamma75(E19) isoleucine leads to threonine found in a family with Hb G Philadelphia, beta-chain deficiency and a Lepore-like haemoglobin indistinguishable from Hb A2". Acta Haematol. 53 (6): 347–55. doi:10.1159/000208204. PMID 808940.
- Proudfoot NJ, Brownlee GG (1976). "3' non-coding region sequences in eukaryotic messenger RNA". Nature. 263 (5574): 211–4. doi:10.1038/263211a0. PMID 822353.
- Marotta CA, Forget BG, Cohne-Solal M, et al. (1977). "Human beta-globin messenger RNA. I. Nucleotide sequences derived from complementary RNA". J. Biol. Chem. 252 (14): 5019–31. PMID 873928.
- Frier JA, Perutz MF (1977). "Structure of human foetal deoxyhaemoglobin". J. Mol. Biol. 112 (1): 97–112. doi:10.1016/S0022-2836(77)80158-7. PMID 881729.
- Ahern E, Holder W, Ahern V, et al. (1975). "Haemoglobin F Victoria Jubilee (alpha 2 A gamma 2 80 Asp-Try)". Biochim. Biophys. Acta. 393 (1): 188–94. doi:10.1016/0005-2795(75)90230-5. PMID 1138921.
- Waye JS, Cai SP, Eng B, et al. (1993). "Clinical course and molecular characterization of a compound heterozygote for sickle hemoglobin and hemoglobin Kenya". Am. J. Hematol. 41 (4): 289–91. doi:10.1002/ajh.2830410413. PMID 1283810.
- Bailey WJ, Hayasaka K, Skinner CG, et al. (1994). "Reexamination of the African hominoid trichotomy with additional sequences from the primate beta-globin gene cluster". Mol. Phylogenet. Evol. 1 (2): 97–135. doi:10.1016/1055-7903(92)90024-B. PMID 1342932.
- Gottardi E, Losekoot M, Fodde R, et al. (1992). "Rapid identification by denaturing gradient gel electrophoresis of mutations in the gamma-globin gene promoters in non-deletion type HPFH". Br. J. Haematol. 80 (4): 533–8. doi:10.1111/j.1365-2141.1992.tb04569.x. PMID 1374633.
- Berry M, Grosveld F, Dillon N (1992). "A single point mutation is the cause of the Greek form of hereditary persistence of fetal haemoglobin". Nature. 358 (6386): 499–502. doi:10.1038/358499a0. PMID 1379347.
- Loudianos G, Moi P, Lavinha J, et al. (1993). "Normal delta-globin gene sequences in Sardinian nondeletional delta beta-thalassemia". Hemoglobin. 16 (6): 503–9. doi:10.3109/03630269208993118. PMID 1487421.
- Fucharoen S, Shimizu K, Fukumaki Y (1990). "A novel C-T transition within the distal CCAAT motif of the G gamma-globin gene in the Japanese HPFH: implication of factor binding in elevated fetal globin expression". Nucleic Acids Res. 18 (17): 5245–53. doi:10.1093/nar/18.17.5245. PMC 332148. PMID 1698280.
- Plaseska D, Kutlar F, Wilson JB, et al. (1991). "Hb F-Jiangsu, the first gamma chain variant with a valine----methionine substitution: alpha 2A gamma 2 134(H12)Val----Met". Hemoglobin. 14 (2): 177–83. doi:10.3109/03630269009046959. PMID 1703137.
PDB gallery |
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| 1fdh: STRUCTURE OF HUMAN FOETAL DEOXYHAEMOGLOBIN |
| 1i3d: HUMAN CARBONMONOXY HEMOGLOBIN BART'S (GAMMA4) |
| 1i3e: HUMAN AZIDO-MET HEMOGLOBIN BART'S (GAMMA4) |
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Globins | |
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see also disorders of globin and globulin proteins |