Download Gene Section JUNB (jun B proto-oncogene) Atlas of Genetics and Cytogenetics

Atlas of Genetics and Cytogenetics
in Oncology and Haematology
OPEN ACCESS JOURNAL AT INIST-CNRS
Gene Section
Mini Review
JUNB (jun B proto-oncogene)
Fei Chen
Health Effects Laboratory Division, NIOSH, 1095 Willowdale Rd, Morgantown, WV 26505, USA (FC)
Published in Atlas Database: January 2003
Online updated version: http://AtlasGeneticsOncology.org/Genes/JUNBID178.html
DOI: 10.4267/2042/37952
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 2.0 France Licence.
© 2003 Atlas of Genetics and Cytogenetics in Oncology and Haematology
Localisation
Identity
Nuclear.
Other names: JUN-B; JUN protooncogene homolog B
HGNC (Hugo): JUNB
Location: 19p13.2
Function
JUNB is a member of JUN family (JUN, JUNB and
JUND) that can dimerize with one another, or with
members of Fos and ATF families, to form AP-1
transcription factor. Comparing with JUN, the
transactivation activity of JUNB is much weaker. Due
to the small differences on the amino acid sequences in
the basic DNA bindind domain, and leucine zipper
domain, JUNB requires multiple AP-1 DNA binding
sites for sufficient DNA binding. A number of studies
demonstrated that JUNB antagonizes the functions of
JUN in cell cycle regulation, proliferation and
transformation by competing with JUN to form less
efficient transactivating dimers. Thus, JUNB was
considered as a tumor suppressor. In gene knockout
studies, mice lacking Jun gene die during embryonic
day 12.5 and 13.5, whereas embryos lacking JunB die
earlier, around day 9.5, owing to vascular defects in the
placenta and extraembryonic tissue. Interestingly; gene
knock-in experiment indicated that JUNB could
partially substitute the activities of JUN in mouse
development and cell proliferation. As possible
explanation for this is that in presence of JUN, JUNB is
a negative regulator for JUN. In contrast, in the absence
of JUN, JUNB may substitute JUN and activate AP-1
target genes required for development and cell
proliferation.
DNA/RNA
Description
The JUNB gene maps on chromosome 19p13.2
covering 1820 bp.
Transcription
It contains no confirmed intron. Therefore, no
alternative splicing transcripts have been identified.
Protein
Description
JUNB has 347 amino acids with a predicted molecular
weight 35,9 kD. Structurally, JUNB is similar to JUN,
which contains a JNK docking site, nuclear localization
signal, basic domain for DNA binding and a leucine
zipper domain for dimerization. However, JUNB does
not contain a JUNK phosphorylation site. Thus, the
transa-ctivation activity of JUNB is not regulated by
JNK.
Expression
Ubiquitously expressed.
Atlas Genet Cytogenet Oncol Haematol. 2003; 7(2)
87
JUNB (jun B proto-oncogene)
Chen F
Implicated in
References
Inflammation, cancer
Schorpp-Kistner M, Wang ZQ, Angel P, Wagner EF. JunB is
essential for mammalian placentation. EMBO J. 1999 Feb
15;18(4):934-48
Oncogenesis
Decreased expression of JUNB has been observed in
certain human cancer. However, no mutation,
rearrangement or amplification of JunB gene has been
reported.
Passegué E, Jochum W, Behrens A, Ricci R, Wagner EF.
JunB can substitute for Jun in mouse development and cell
proliferation. Nat Genet. 2002 Feb;30(2):158-66
This article should be referenced as such:
Chen F. JUNB (jun B proto-oncogene). Atlas Genet Cytogenet
Oncol Haematol. 2003; 7(2):87-88.
Atlas Genet Cytogenet Oncol Haematol. 2003; 7(2)
88