Histone variant are non-allelic forms of the conventional histones. They are expressed at very low levels compared to their conventional counterparts. All the conventional histones, except H4, have histone variants. Together with histone modifications and chromatin remodeling machines, the incorporation of histone variants into the nucleosome is one of the main strategies that the cell uses to regulate transcription, repair, chromosome assembly and segregation. The exact role of the histone variants in these processes is far from clear, but the emerging picture is that the presence of histone variants confers novel structural and functional properties of the nucleosome which affect the chromatin dynamics. In this article we will discuss the functional significance of histone variants on chromatin function and its link to disease manifestation
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Abbott DW, Ivanova VS, Wang X, Bonner WM, Ausio J (2001) Characterization of the stability and folding of H2A.Z chromatin particles: implications for transcriptional activation. J Biol Chem 276: 41945–41949
Adam M, Robert F, Larochelle M, Gaudreau L (2001) H2A.Z is required for global chromatin integrity and for recruitment of RNA polymerase II under specific conditions. Mol Cell Biol 21: 6270–6279
Adams RR, Carmena M, Earnshaw WC (2001) Chromosomal passengers and the (aurora) ABCs of mitosis. Trends Cell Biol 11: 49–54
Allen MD, Buckle AM, Cordell SC, Lowe J, Bycroft M (2003) The crystal structure of AF1521 a protein from Archaeoglobus fulgidus with homology to the non-histone domain of macroH2A. J Mol Biol 330: 503–511
Angelov D, Molla A, Perche PY, Hans F, Cote J, Khochbin S, Bouvet P, Dimitrov S (2003) The histone variant macroH2A interferes with transcription factor binding and SWI/SNF nucleosome remodeling. Mol Cell 11: 1033–1041
Angelov D, Verdel A, An W, Bondarenko V, Hans F, Doyen CM, Studitsky VM, Hamiche A, Roeder RG, Bouvet P, Dimitrov S (2004) SWI/SNF remodeling and p300-dependent transcription of histone variant H2ABbd nucleosomal arrays. Embo J 23: 3815–3824
Arents G, Moudrianakis EN (1993) Topography of the histone octamer surface: repeating structural motifs utilized in the docking of nucleosomal DNA. Proc Natl Acad Sci U S A 90: 10489–10493
Arents G, Burlingame RW, Wang B-C, Love WE, Moudrianakis EN (1991) The nucleosomal core histone octamer at 3.1 A resolution: A tripartite protein assembly and a left-handed superhelix. Proc Natl Acad Sci U S A 88: 10148–10152
Bao Y, Konesky K, Park YJ, Rosu S, Dyer PN, Rangasamy D, Tremethick DJ, Laybourn PJ, Luger K (2004) Nucleosomes containing the histone variant H2A.Bbd organize only 118 base pairs of DNA. Embo J 23: 3314–3324
Bassing CH, Alt FW (2004) H2AX may function as an anchor to hold broken chromosomal DNA ends in close proximity. Cell Cycle 3: 149–153
Bassing CH, Suh H, Ferguson DO, Chua KF, Manis J, Eckersdorff M, Gleason M, Bronson R, Lee C, Alt FW (2003) Histone H2AX: a dosage-dependent suppressor of oncogenic translocations and tumors. Cell 114: 359–370
Beato M, Eisfeld K (1997) Transcription factor access to chromatin. Nucleic Acids Res 25: 3559–3563
Becker PB (2002) Nucleosome sliding: facts and fiction. Embo J 21: 4749–4753
Bekker-Jensen S, Lukas C, Kitagawa R, Melander F, Kastan MB, Bartek J, Lukas J (2006) Spatial organization of the mammalian genome surveillance machinery in response to DNA strand breaks. J Cell Biol 173: 195–206
Blower MD, Karpen GH (2001) The role of Drosophila CID in kinetochore formation, cell-cycle progression and heterochromatin interactions. Nat Cell Biol 3: 730–739
Blower MD, Sullivan BA, Karpen GH (2002) Conserved organization of centromeric chromatin in flies and humans. Dev Cell 2: 319–330
Bosch A, Suau P (1995) Changes in core histone variant composition in differentiating neurons: the roles of differential turnover and synthesis rates. Eur J Cell Biol 68: 220–225
Boulard M, Gautier T, Mbele GO, Gerson V, Hamiche A, Angelov D, Bouvet P, Dimitrov S (2006) The NH2 tail of the novel histone variant H2BFWT exhibits properties distinct from conventional H2B with respect to the assembly of mitotic chromosomes. Mol Cell Biol 26: 1518–1526
Burma S, Chen BP, Murphy M, Kurimasa A, Chen DJ (2001) ATM phosphorylates histone H2AX in response to DNA double-strand breaks. J Biol Chem 276: 42462–42467
Celeste A, Petersen S, Romanienko PJ, Fernandez-Capetillo O, Chen HT, Sedelnikova OA, Reina-San-Martin B, Coppola V, Meffre E, Difilippantonio MJ, Redon C, Pilch DR, Olaru A, Eckhaus M, Camerini-Otero RD, Tessarollo L, Livak F, Manova K, Bonner WM, Nussenzweig MC, Nussenzweig A (2002) Genomic instability in mice lacking histone H2AX. Science 296: 922–927
Celeste A, Difilippantonio S, Difilippantonio MJ, Fernandez-Capetillo O, Pilch DR, Sedelnikova OA, Eckhaus M, Ried T, Bonner WM, Nussenzweig A (2003a) H2AX haploinsufficiency modifies genomic stability and tumor susceptibility. Cell 114: 371–383
Celeste A, Fernandez-Capetillo O, Kruhlak MJ, Pilch DR, Staudt DW, Lee A, Bonner RF, Bonner WM, Nussenzweig A (2003b) Histone H2AX phosphorylation is dispensable for the initial recognition of DNA breaks. Nat Cell Biol 5: 675–679
Chadwick BP, Willard HF (2001a) Histone H2A variants and the inactive X chromosome: identification of a second macroH2A variant. Hum Mol Genet 10: 1101–1113
Chadwick BP, Willard HF (2001b) A novel chromatin protein, distantly related to histone H2A, is largely excluded from the inactive X chromosome. J Cell Biol 152: 375–384
Chadwick BP, Willard HF (2002) Cell cycle-dependent localization of macroH2A in chromatin of the inactive X chromosome. J Cell Biol 157: 1113–1123
Chadwick BP, Valley CM, Willard HF (2001) Histone variant macroH2A contains two distinct macrochromatin domains capable of directing macroH2A to the inactive X chromosome. Nucleic Acids Res. 29: 2699–2705
Chevaillier P, Mauro N, Feneux D, Jouannet P, David G (1987) Anomalous protein complement of sperm nuclei in some infertile men. Lancet 2: 806–807
Choo JH, Kim JD, Chung JH, Stubbs L, Kim J (2006) Allele-specific deposition of macroH2A1 in imprinting control regions. Hum Mol Genet 15: 717–724
Churikov D, Siino J, Svetlova M, Zhang K, Gineitis A, Morton Bradbury E, Zalensky A (2004) Novel human testis-specific histone H2B encoded by the interrupted gene on the X chromosome. Genomics 84: 745–756
Clarkson MJ, Wells JR, Gibson F, Saint R, Tremethick DJ (1999) Regions of variant histone His2AvD required for Drosophila development. Nature 399: 694–697
Costanzi C, Pehrson JR (1998) Histone macroH2A1 is concentrated in the inactive X chromosome of female mammals. Nature 393: 599–601
Costanzi C, Pehrson JR (2001) MacroH2A2, a new member of the macroH2A core histone family. J Biol Chem 276: 21776–21784
Dhillon N, Kamakaka RT (2000) A histone variant, Htz1p, and a Sir1p-like protein, Esc2p, mediate silencing at HMR. Mol Cell 6: 769–780
Doenecke D, Albig W, Bode C, Drabent B, Franke K, Gavenis K, Witt O (1997) Histones: genetic diversity and tissue-specific gene expression. Histochem Cell Biol 107: 1–10
Downs JA, Allard S, Jobin-Robitaille O, Javaheri A, Auger A, Bouchard N, Kron SJ, Jackson SP, Cote J (2004) Binding of chromatin-modifying activities to phosphorylated histone H2A at DNA damage sites. Mol Cell 16: 979–990
Doyen CM, An W, Angelov D, Bondarenko V, Mietton F, Studitsky VM, Hamiche A, Roeder RG, Bouvet P, Dimitrov S (2006) Mechanism of polymerase II transcription repression by the histone variant macroH2A. Mol Cell Biol 26: 1156–1164
Faast R, Thonglairoam V, Schulz TC, Beall J, Wells JR, Taylor H, Matthaei K, Rathjen PD, Tremethick DJ, Lyons I (2001) Histone variant H2A.Z is required for early mammalian development. Curr Biol 11: 1183–1187
Fan JY, Gordon F, Luger K, Hansen JC, Tremethick DJ (2002) The essential histone variant H2A.Z regulates the equilibrium between different chromatin conformational states. Nat Struct Biol 9:172–176
Fan JY, Rangasamy D, Luger K, Tremethick DJ (2004) H2A.Z alters the nucleosome surface to promote HP1alpha-mediated chromatin fiber folding. Mol Cell 16: 655–661
Fernandez-Capetillo O, Chen HT, Celeste A, Ward I, Romanienko PJ, Morales JC, Naka K, Xia Z, Camerini-Otero RD, Motoyama N, Carpenter PB, Bonner WM, Chen J, Nussenzweig A (2002) DNA damage-induced G2-M checkpoint activation by histone H2AX and 53BP1. Nat Cell Biol 4: 993–997
Fernandez-Capetillo O, Mahadevaiah SK, Celeste A, Romanienko PJ, Camerini-Otero RD, Bonner WM, Manova K, Burgoyne P, Nussenzweig A (2003) H2AX is required for chromatin remodeling and inactivation of sex chromosomes in male mouse meiosis. Dev Cell 4: 497–508
Fernandez-Capetillo O, Lee A, Nussenzweig M, Nussenzweig A (2004) H2AX: the histone guardian of the genome. DNA Repair (Amst) 3: 959–967
Foltz DR, Jansen LE, Black BE, Bailey AO, Yates JR, Cleveland DW (2006) The human CENP-A centromeric nucleosome-associated complex. Nat Cell Biol 8:458–469
Foresta C, Zorzi M, Rossato M, Varotto A (1992) Sperm nuclear instability and staining with aniline blue: abnormal persistence of histones in spermatozoa in infertile men. Int J Androl 15: 330–337
Fukagawa T, Nogami M, Yoshikawa M, Ikeno M, Okazaki T, Takami Y, Nakayama T, Oshimura M (2004) Dicer is essential for formation of the heterochromatin structure in vertebrate cells. Nat Cell Biol 6: 784–791
Furuyama T, Dalal Y, Henikoff S (2006) Chaperone-mediated assembly of centromeric chromatin in vitro. Proc Natl Acad Sci U S A 103: 6172–6177
Gautier T, Abbott DW, Molla A, Verdel A, Ausio J, Dimitrov S (2004) Histone variant H2ABbd confers lower stability to the nucleosome. EMBO Rep 5: 715–720
Gineitis AA, Zalenskaya IA, Yau PM, Bradbury EM, Zalensky AO (2000) Human sperm telomere-binding complex involves histone H2B and secures telomere membrane attachment. J Cell Biol 151: 1591–1598
Govin J, Caron C, Rousseaux S, Khochbin S (2005) Testis-specific histone H3 expression in somatic cells. Trends Biochem Sci 30: 357–359
Grigoryev SA, Nikitina T, Pehrson JR, Singh PB, Woodcock CL (2004) Dynamic relocation of epigenetic chromatin markers reveals an active role of constitutive heterochromatin in the transition from proliferation to quiescence. J Cell Sci 117: 6153–6162
Guillemette B, Bataille AR, Gevry N, Adam M, Blanchette M, Robert F, Gaudreau L (2005) Variant histone H2A.Z is globally localized to the promoters of inactive yeast genes and regulates nucleosome positioning. PLoS Biol, 3, e384
Henikoff S, Ahmad K (2005) Assembly of variant histones into chromatin. Annu Rev Cell Dev Biol 21, 133–153
Henikoff S, Furuyama T, Ahmad K (2004) Histone variants, nucleosome assembly and epigenetic inheritance. Trends Genet 20: 320–326
Heun P, Erhardt S, Blower MD, Weiss S, Skora AD, Karpen GH (2006) Mislocalization of the Drosophila centromere-specific histone CID promotes formation of functional ectopic kinetochores. Dev Cell 10: 303–315
Hofmann N, Hilscher B (1991) Use of aniline blue to assess chromatin condensation in morphologically normal spermatozoa in normal and infertile men. Hum Reprod 6: 979–982
Howman EV, Fowler KJ, Newson AJ, Redward S, MacDonald AC, Kalitsis P, Choo KH (2000) Early disruption of centromeric chromatin organization in centromere protein A (Cenpa) null mice. Proc Natl Acad Sci U S A 97: 1148–1153
Kamakaka RT, Biggins S (2005) Histone variants: deviants? Genes Dev 19: 295–310
Karras GI, Kustatscher G, Buhecha HR, Allen MD, Pugieux C, Sait F, Bycroft M, Ladurner AG (2005) The macro domain is an ADP-ribose binding module. Embo J 24: 1911–1920
Kustatscher G, Hothorn M, Pugieux C, Scheffzek K, Ladurner AG (2005) Splicing regulates NAD metabolite binding to histone macroH2A. Nat Struct Mol Biol 12: 624–625
Ladurner AG (2003) Inactivating chromosomes: a macro domain that minimizes transcription. Mol Cell 12: 1–3
Larochelle M, Gaudreau L (2003) H2A.Z has a function reminiscent of an activator required for preferential binding to intergenic DNA. Embo J 22: 4512–4522
Li B, Pattenden SG, Lee D, Gutierrez J, Chen J, Seidel C, Gerton J, Workman JL (2005) Preferential occupancy of histone variant H2AZ at inactive promoters influences local histone modifications and chromatin remodeling. Proc Natl Acad Sci U S A 102: 18385–18390
Loyola A, Almouzni G (2004) Histone chaperones, a supporting role in the limelight. Biochim Biophys Acta 1677: 3–11
Luger K, Mäder, AW., Richmond RK, Sargent DF, Richmond TJ (1997) Crystal structure of the nucleosome core particle at 2.8 A resolution. Nature 389: 251–260
Ma Y, Jacobs SB, Jackson-Grusby L, Mastrangelo MA, Torres-Betancourt JA, Jaenisch R, Rasmussen TP (2005) DNA CpG hypomethylation induces heterochromatin reorganization involving the histone variant macroH2A. J Cell Sci 118: 1607–1616
Malik HS, Henikoff S (2003) Phylogenomics of the nucleosome. Nat Struct Biol 10: 882–891
Martzen MR, McCraith SM, Spinelli SL, Torres FM, Fields S, Grayhack EJ, Phizicky EM (1999) A biochemical genomics approach for identifying genes by the activity of their products. Science 286: 1153–1155
Meneghini MD, Wu M, Madhani HD (2003) Conserved histone variant H2A.Z protects euchromatin from the ectopic spread of silent heterochromatin. Cell 112: 725–736
Mermoud JE, Costanzi C, Pehrson JR, Brockdorff N (1999) Histone macroH2A1.2 relocates to the inactive X chromosome after initiation and propagation of X-inactivation. J Cell Biol 147: 1399–1408
Mito Y, Henikoff JG, Henikoff S (2005) Genome-scale profiling of histone H3.3 replacement patterns. Nat Genet 37: 1090–1097
Mizuguchi G, Shen X, Landry J, Wu WH, Sen S, Wu C (2003) ATP-Driven Exchange of Histone H2AZ Variant Catalyzed by SWR1 Chromatin Remodeling Complex. Science
Monni O, Knuutila S (2001) 11q deletions in hematological malignancies. Leuk Lymphoma 40: 259–266
Morrison AJ, Highland J, Krogan NJ, Arbel-Eden A, Greenblatt JF, Haber JE, Shen X (2004) INO80 and gamma-H2AX interaction links ATP-dependent chromatin remodeling to DNA damage repair. Cell 119: 767–775
Moss SB, Challoner PB, Groudine M (1989) Expression of a novel histone 2B during mouse spermiogenesis. Dev Biol 133: 83–92
Oegema K, Desai A, Rybina S, Kirkham M, Hyman AA (2001) Functional analysis of kinetochore assembly in Caenorhabditis elegans. J Cell Biol 153: 1209–1226
Okada M, Cheeseman IM, Hori T, Okawa K, McLeod IX, Yates JR, Desai A, Fukagawa T (2006) The CENP-H-I complex is required for the efficient incorporation of newly synthesized CENP-A into centromeres. Nat Cell Biol
Palmer DK, O’Day K, Margolis RL (1989) Biochemical analysis of CENP-A, a centromeric protein with histone-like properties. Prog Clin Biol Res 318: 61–72
Palmer DK, O’Day K, Margolis RL (1990) The centromere specific histone CENP-A is selectively retained in discrete foci in mammalian sperm nuclei. Chromosoma 100: 32–36
Pandey NB, Marzluff WF (1987) The stem-loop structure at the 3’ end of histone mRNA is necessary and sufficient for regulation of histone mRNA stability. Mol Cell Biol 7: 4557–4559
Pehrson J, Fuji RN (1998) Evolutionary conservation of histone macroH2A subtypes and domains. Nucl Acids Res 26: 2837–2842
Pehrson JR, Fried VA (1992) MacroH2A, a core histone containing a large nonhistone region. Science 257: 1398–1400
Perche P, Vourch C, Souchier C, Robert-Nicoud M, Dimitrov S, Khochbin C (2000) Higher concentrations of histone macroH2A in the Barr body are correlated with higher nucleosome density. Curr Biol 10: 1531–1534
Poccia DL, Green GR (1992) Packaging and unpackaging the sea urchin sperm genome. Trends Biochem Sci 17: 223–227
Raisner RM, Hartley PD, Meneghini MD, Bao MZ, Liu CL, Schreiber SL, Rando OJ, Madhani HD (2005) Histone Variant H2A.Z Marks the 5’ Ends of Both Active and Inactive Genes in Euchromatin. Cell 123: 233–248
Rangasamy D, Berven L, Ridgway P, Tremethick DJ (2003) Pericentric heterochromatin becomes enriched with H2A.Z during early mammalian development. Embo J 22: 1599–1607
Rangasamy D, Greaves I, Tremethick DJ (2004) RNA interference demonstrates a novel role for H2A.Z in chromosome segregation. Nat Struct Mol Biol 11: 650–655
Rasmussen TP, Mastrangelo MA, Eden A, Pehrson JR, Jaenisch R (2000) Dynamic relocalization of histone MacroH2A1 from centrosomes to inactive X chromosomes during X inactivation. J Cell Biol 150: 1189–1198
Redon C, Pilch D, Rogakou E, Sedelnikova O, Newrock K, Bonner W (2002) Histone H2A variants H2AX and H2AZ. Curr Opin Genet Dev 12: 162–169
Rogakou EP, Pilch DR, Orr AH, Ivanova VS, Bonner WM (1998) DNA double-stranded breaks induce histone H2AX phosphorylation on serine 139. J Biol Chem 273: 5858–5868
Rogakou EP, Boon C, Redon C, Bonner WM (1999) Megabase chromatin domains involved in DNA double-strand breaks in vivo. J Cell Biol 146: 905–916
Santisteban MS, Kalashnikova T, Smith MM (2000) Histone H2A.Z regulates transcription and is partially redundant with nucleosome remodeling complexes. Cell 103: 411–422
Sarma K, Reinberg D (2005) Histone variants meet their match. Nat Rev Mol Cell Biol 6: 139–149
Savitsky K, Bar-Shira A, Gilad S, Rotman G, Ziv Y, Vanagaite L, Tagle DA, Smith S, Uziel T, Sfez S et al (1995) A single ataxia telangiectasia gene with a product similar to PI-3 kinase. Science 268: 1749–1753
Siino JS, Nazarov IB, Svetlova MP, Solovjeva LV, Adamson RH, Zalenskaya IA, Yau PM, Bradbury EM, Tomilin NV (2002) Photobleaching of GFP-labeled H2AX in chromatin: H2AX has low diffusional mobility in the nucleus. Biochem Biophys Res Commun 297: 1318–1323
Stiff T, Shtivelman E, Jeggo P, Kysela B (2004) AHNAK interacts with the DNA ligase IV-XRCC4 complex and stimulates DNA ligase IV-mediated double-stranded ligation. DNA Repair (Amst) 3: 245–256
Strahl BD, Allis CD (2000) The language of covalent histone modifications. Nature 403: 41–45
Suto RK, Clarkson MJ, Tremethick DJ, Luger K (2000) Crystal structure of a nucleosome core particle containing the variant histone H2A.Z. Nature Struct. Biol. 7: 1121–1124
Swaminathan J, Baxter EM, Corces VG (2005) The role of histone H2Av variant replacement and histone H4 acetylation in the establishment of Drosophila heterochromatin. Genes Dev 19: 65–76
Tagami H, Ray-Gallet D, Almouzni G, Nakatani Y (2004) Histone H3.1 and H3.3 complexes mediate nucleosome assembly pathways dependent or independent of DNA synthesis. Cell 116: 51–61
Taneja N, Davis M, Choy JS, Beckett MA, Singh R, Kron SJ, Weichselbaum RR (2004) Histone H2AX phosphorylation as a predictor of radiosensitivity and target for radiotherapy. J Biol Chem 279: 2273–2280
Tanphaichitr N, Sobhon P, Taluppeth N, Chalermisarachai P (1978) Basic nuclear proteins in testicular cells and ejaculated spermatozoa in man. Exp Cell Res 117: 347–356
Tomonaga T, Matsushita K, Yamaguchi S, Oohashi T, Shimada H, Ochiai T, Yoda K, Nomura F (2003) Overexpression and mistargeting of centromere protein-A in human primary colorectal cancer. Cancer Res 63: 3511–3516
Tsanev R, Russev G, Pashev I, Zlatanova J (1993) Replication and transcription of chromatin. CRC Press, Boca Raton, FI
Unni E, Zhang Y, Kangasniemi M, Saperstein W, Moss SB, Meistrich ML (1995) Stage-specific distribution of the spermatid-specific histone 2B in the rat testis. Biol Reprod 53: 820–826
van Attikum H, Fritsch O, Hohn B, Gasser SM (2004) Recruitment of the INO80 complex by H2A phosphorylation links ATP-dependent chromatin remodeling with DNA double-strand break repair. Cell 119: 777–788
van Holde K (1988) Chromatin. Springer-Verlag KG, Berlin, Germany
Van Hooser AA, Ouspenski II, Gregson HC, Starr DA, Yen TJ, Goldberg ML, Yokomori K, Earnshaw WC, Sullivan KF, Brinkley BR (2001) Specification of kinetochore-forming chromatin by the histone H3 variant CENP-A. J Cell Sci 114: 3529–3542
van Roijen HJ, Ooms MP, Spaargaren MC, Baarends WM, Weber RF, Grootegoed JA, Vreeburg JT (1998) Immunoexpression of testis-specific histone 2B in human spermatozoa and testis tissue. Hum Reprod 13: 1559–1566
Yoda K, Ando S, Morishita S, Houmura K, Hashimoto K, Takeyasu K, Okazaki T (2000) Human centromere protein A (CENP-A) can replace histone H3 in nucleosome reconstitution in vitro. Proc Natl Acad Sci U S A 97: 7266–7271
Zhang H, Roberts DN, Cairns BR (2005a) Genome-wide dynamics of Htz1, a histone H2A variant that poises repressed/basal promoters for activation through histone loss. Cell 123: 219–231
Zhang R, Poustovoitov MV, Ye X, Santos HA, Chen W, Daganzo SM, Erzberger JP, Serebriiskii IG, Canutescu AA, Dunbrack RL, Pehrson JR, Berger JM, Kaufman PD, Adams PD (2005b) Formation of MacroH2A-containing Senescence-associated heterochromatin foci and senescence driven by ASF1a and HIRA. Dev Cell 8: 19–30
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Boulard, M., Bouvet, P., Kundu, T.K., Dimitrov, S. (2007). Histone Variant Nucleosomes. In: Kundu, T.K., et al. Chromatin and Disease. Subcellular Biochemistry, vol 41. Springer, Dordrecht. https://doi.org/10.1007/1-4020-5466-1_4
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