Review on IKZF2 (IKAROS family zinc finger 2), with data on DNA, on the protein encoded, and where the gene is implicated

Smale, Stephen

Sridharan, Rupa

Atlas of Genetics and Cytogenetics in Oncology and Haematology

I-Revues

  
 
 
 
 
Gene Section 
Mini Review 
 
Atlas Genet Cytogenet Oncol Haematol. 2007;11(4)  270 
Atlas of Genetics and Cytogenetics 
in Oncology and Haematology                         
                         OPEN ACCESS JOURNAL AT INIST-CNRS 
IKZF2 (Ikaros family zinc finger 2) 
Rupa Sridharan, Stephen Smale 
Room 6730 MacDonald Research Laboratories, Howard Hughes Medical Institute, 675 Charles Young Drive 
South, University of California, Los Angeles, CA 90095-1662, USA 
Published in Atlas Database: April 2007 
Online updated version: http://AtlasGeneticsOncology.org/Genes/IKZF2ID42885ch2q34.html  
DOI: 10.4267/2042/15940 
This work is licensed under a Creative Commons Attribution-Non-commercial-No Derivative Works 2.0 France Licence. 
© 2007 Atlas of Genetics and Cytogenetics in Oncology and Haematology 
 
Identity 
Hugo: IKZF2 
Other names: Helios; ZNFN1A2; Mouse Ikzf2 
Location: 2q34 
Note: Belongs to the Ikaros family of zinc finger 
containing DNA binding proteins. 
DNA/RNA 
Description 
143 kb encoding 7 exons. 
Transcription 
12 kb transcript, alternatively spliced to give two 
predominant isoforms. 
Protein 
Note: 526 amino acids. Mouse protein migrates at 70 
kD. 
 
 
Helios with the zinc finger domain shown as blocks and the 
exon junctions in black lines. 
Description 
Largest isoform contains four N-terminal zinc fingers 
used for DNA binding and two C terminal zinc fingers 
for homodimerization and heterodimerization with 
other Ikaros family members. 
Expression 
Largely restricted to the thymus. In mice, besides 
thymocytes and T cells, low levels are found in proB 
cells and bone marrow multipotent progenitors. 
Localisation 
Nuclear. Often localizes to the pericentric 
heterochromatin as punctate spots in cycling cells, with 
diffuse nuclear localization in non-cycling cells. 
Function 
Helios is thought to be important for T cell 
development and may function as a repressor of 
transcription. However, Helios mutant mice have not 
been reported. In mice, Helios can recruit the NuRD 
chromatin remodeling complex to the pericentric 
heterochromatin. 
Homology 
High level of identity to Ikaros over the zinc finger 
domains. 
Implicated in 
Leukemia 
Note: Shorter isoforms of Helios are expressed in 
certain human leukemias. They may function as 
dominant negative inhibitors of full-length proteins due 
to the lack of DNA binding domain. However, 
dominant negative functions have not been 
demonstrated experimentally. 
Disease 
T-cell acute lymphoblastic leukemia. 
Lymphoma 
Note: Overexpression of Helios in B cells of mice 
promotes lymphomagenesis. Overexpression of a DNA 
binding mutant in hematopoietic progenitors leads to 
aggressive and transplantable T cell lymphomas in 60% 
of the mice. 
 
 
 
IKZF2 (Ikaros family zinc finger 2) Sridharan R, Smale S 
 
 
 
 
 
Atlas Genet Cytogenet Oncol Haematol. 2007;11(4)  271 
References 
Hahm K, Cobb BS, McCarty AS, Brown KE, Klug CA, Lee R, 
Akashi K, Weissman IL, Fisher AG, Smale ST. Helios, a T cell-
restricted Ikaros family member that quantitatively associates 
with Ikaros at centromeric heterochromatin. Genes Dev 
1998;12(6):782-796. 
Kelley CM, Ikeda T, Koipally J, Avitahl N, Wu L, Georgopoulos 
K, Morgan BA. Helios, a novel dimerization partner of Ikaros 
expressed in the earliest hematopoietic progenitors. Curr Biol 
1998;8(9):508-515. 
Hosokawa Y, Maeda Y, Seto M. Human Helios, an Ikaros-
related zinc finger DNA binding protein: cDNA cloning and 
tissue expression pattern. Immunogenetics 1999;50(1-2):106-
108. 
Nakase K, Ishimaru F, Fujii K, Tabayashi T, Kozuka T, Sezaki 
N, Matsuo Y, Harada M. Overexpression of novel short 
isoforms of Helios in a patient with T-cell acute lymphoblastic 
leukemia. Exp Hematol 2002;30(4):313-317. 
Dovat S, Montecino-Rodriguez E, Schuman V, Teitell MA, 
Dorshkind K, Smale ST. Transgenic expression of Helios in B 
lineage cells alters B cell properties and promotes 
lymphomagenesis. J Immunol 2005;175(6):3508-3515. 
Zhang Z, Swindle CS, Bates JT, Ko R, Cotta CV, Klug CA. 
Expression of a non-DNA-binding isoform of Helios induces T-
cell lymphoma in mice. Blood 2007;109(5):2190-2197. 
This article should be referenced as such: 
Sridharan R, Smale S. IKZF2 (Ikaros family zinc finger 2). Atlas 
Genet Cytogenet Oncol Haematol.2007;11(4):270-271.  
 
 
 


IKZF2 (IKAROS family zinc finger 2)

Abstract

Similar works

Full text

Available Versions

I-Revues