Se. Salghetti et al., Functional overlap of sequences that activate transcription and signal ubiquitin-mediated proteolysis, P NAS US, 97(7), 2000, pp. 3118-3123
Citations number
49
Categorie Soggetti
Multidisciplinary
Journal title
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
Many transcription factors, particularly those involved in the control of c
ell growth, are unstable proteins destroyed by ubiquitin-mediated proteolys
is. In a previous study of sequences targeting the transcription factor Myc
for destruction, we observed that the region in Myc signaling ubiquitin-me
diated proteolysis overlaps closely with the region in Myc that activates t
ranscription. Here, we present evidence that the overlap of these two activ
ities is not unique to Myc, but reflects a more general phenomenon. We show
that a similar overlap of activation domains and destruction elements occu
rs in other unstable transcription factors and report a close correlation b
etween the ability of an acidic activation domain to activate transcription
and to signal proteolysis. We also show that destruction elements from yea
st cyclins, when tethered to a DNA-binding domain, activate transcription.
The intimate overlap of activation domains and destruction elements reveals
an unexpected convergence of two very different processes and suggests tha
t transcription factors may he destroyed because of their ability to activa
te transcription.