Acetylation of ?-Catenin by CREB-binding Protein (CBP)*
Received for publication, February 5, 2002, and in revised form, April 18, 2002
Published, JBC Papers in Press, April 24, 2002, DOI 10.1074/jbc.M201196200
Daniel Wolf‡§¶, Marianna Rodova§?, Eric A. Miska‡, James P. Calvet?**, and Tony Kouzarides‡ ‡‡
From the ‡Wellcome/CRC (Cancer Research Campaign) Institute and Department of Pathology, University of Cambridge,
Tennis Court Road, Cambridge CB2 1QR, United Kingdom and ?The University of Kansas Medical Center,
Kansas City, Kansas 66160
Acetylation controls the activity of numerous proteins
involved in regulating gene transcription as well as
many other cellular processes. In this report we show
that the CREB-binding protein (CBP) acetyltransferase
acetylates ?-catenin protein in vivo. ?-Catenin is a cen-
tral component of the Wnt signaling pathway, which is
of key importance in development as well as being heav-
ily implicated in a variety of human cancers. We show
that the CBP-mediated acetylation of ?-catenin occurs
at a single site, lysine 49. Importantly, this lysine is
frequently found mutated in cancer and is in a region of
importance to the regulation of ?-catenin. We show that
mutation of this site leads specifically to an increase in
the ability of ?-catenin to activate the c-myc gene but not
other ?-catenin-regulated genes. This suggests that
acetylation of ?-catenin is involved in regulating Wnt
signaling in a promoter-specific fashion.
The Wnt signaling pathway is involved in numerous devel-
opmental processes (1), and its deregulation is implicated in
the development of cancer (2). ? key component in the Wnt
signaling pathway is the ?-catenin protein, which is responsi-
ble for transducing the Wnt signal from the cytoplasm to the
nucleus where it results in the activation of Wnt-responsive
genes. ?-Catenin was originally identified as a component of
cell-cell adhesion complexes, connecting cadherins to the cy-
toskeleton (3). Subsequently, a large proportion of ?-catenin
was shown to be localized to the cell membrane. This pool of
?-catenin is thought not to be involved in Wnt signaling. The
signaling pool of ?-catenin is relatively small and is found free
in both the cytoplasm and the nucleus where it activates tran-
scription by binding and co-activating the TCF/LEF-11family
of transcription factors.
One of the key aspects of the regulation of ?-catenin is
control of its stability, which in turn is thought to regulate its
translocation into the nucleus (4). ?-Catenin is a target of the
ubiquitin-dependent proteasome degradation pathway (5).
When the Wnt signaling pathway is in the “off” state ?-catenin
is continuously ubiquitinated and degraded. It is the phospho-
rylation of ?-catenin by the GSK3? kinase that targets it for
ubiquitination. Phosphorylation occurs at three serines and a
threonine residue in the N terminus of ?-catenin (6) and po-
tentiates ?-catenin binding to the F-box protein ?-TrCP, which
is a part of the SCF ubiquitin ligase complex responsible for the
ubiquitination of ?-catenin (7). Upon activation of the Wnt
pathway GSK3? no longer phosphorylates ?-catenin due, at
least in part, to the antagonizing function of the disheveled
Deregulation of the Wnt pathway occurs in many types of
cancer and is caused by mutation of many of the Wnt signaling
components (2). In the case of ?-catenin it has been found that
most of the mutations occur in the N terminus at or adjacent to
the phosphorylated serine and threonine residues (see Fig. 1).
Many of these mutations have been shown to stabilize ?-cate-
nin and thus lead to overactivation of the Wnt pathway. This
overactivation is thought in part to promote oncogenesis
through overexpression of TCF/LEF target genes, such as c-
myc and cyclin D1 (8, 9).
CBP/p300 are distinct but related members of a protein
family that participate in many physiological processes includ-
ing proliferation, differentiation, and apoptosis (10). They are
transcriptional co-activators (11) and have an intrinsic histone
acetyltransferase activity (12, 13). CBP/p300 are thought to
activate transcription by relieving chromatin-dependent re-
pression by the acetylation of histones, by acting as a scaffold
for recruiting other co-activator proteins (10), and by acting as
a bridge to the basal transcription machinery (14). Recently it
was reported that ?-catenin is co-activated by CBP/p300, but
this effect seems to be promoter-dependent (15–17).
Histone acetyltransferases are being recognized increasingly
as modifiers of non-histone proteins, and there is a growing
body of evidence supporting the theory that acetylation, like
phosphorylation, is an important regulatory protein modifica-
tion (18). Acetylated proteins include p53 (19), high mobility
group I(Y) (20), and E2F1 (21), and these acetylation events
have been shown to directly affect protein function. For in-
stance, p53 acetylation stimulates the p53 pathway following a
cell’s exposure to UV radiation (22). Here we demonstrate that
?-catenin is acetylated by CBP at a lysine that is often found
mutated in thyroid cancer. A ?-Catenin protein, mutated at
this lysine, can no longer be acetylated by CBP. In addition, we
find that mutation at this site leads to an increase in the ability
of ?-catenin to specifically activate the c-myc gene promoter.
constructs of ?-catenin K49R (pCS2?MMBCmycK49R) and K19R
(pCS2?MMBCmycK19R) have been described previously (5). The 5?
Myc-tagged construct WT ?-catenin and ?-catenin mutated to alanine
at serines 33, 37, and 45 and threonine 41 were gifts from Hans Clevers.
Wild type Myc-tagged ?-catenin in the same background as pCS2?-
MMBCmycK49R was constructed by inserting NcoI-digested human
* This work was supported in part by a grant from the Cancer
Research Campaign. The costs of publication of this article were de-
frayed in part by the payment of page charges. This article must
therefore be hereby marked “advertisement” in accordance with 18
U.S.C. Section 1734 solely to indicate this fact.
§ Both authors contributed equally to this work.
¶ Supported by the Peter Wildy studentship of Gonville and Cauis
** Supported by National Institutes of Health Grants DK53763 and
DK57301 and a Lied Endowed Basic Science Pilot Research Grant.
‡‡ To whom correspondence should be addressed. Tel.: 44-1223-
334111; Fax: 44-1223-334089; E-mail: email@example.com.
1The abbreviations used are: TCF, T-cell factor; LEF, lymphoid en-
hancer factor; CBP, CREB-binding protein; GSK, glycogen synthase
kinase; WT, wild type; P/CAF, p300/CBP-associated factor.
THE JOURNAL OF BIOLOGICAL CHEMISTRY
© 2002 by The American Society for Biochemistry and Molecular Biology, Inc.
Vol. 277, No. 28, Issue of July 12, pp. 25562–25567, 2002
Printed in U.S.A.
This paper is available on line at http://www.jbc.org
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Miska, James P. Calvet and Tony Kouzarides
2002, 277:25562-25567. J. Biol. Chem.
Daniel Wolf, Marianna Rodova, Eric A.
-Catenin by CREB-binding
doi: 10.1074/jbc.M201196200 originally published online April 24, 2002
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