TY - JOUR
T1 - SUMOylation of the lens epithelium-derived growth factor/p75 attenuates its transcriptional activity on the heat shock protein 27 promoter
AU - Bueno, Murilo T.D.
AU - Garcia-Rivera, Jose A.
AU - Kugelman, Jeffrey R.
AU - Morales, Elisa
AU - Rosas-Acosta, Germán
AU - Llano, Manuel
PY - 2010/6/4
Y1 - 2010/6/4
N2 - Lens epithelium-derived growth factor (LEDGF) proteins p75 and p52 are transcriptional coactivators that connect sequence-specific activators to the basal transcription machinery. We have found that these proteins are posttranslationally modified by SUMO (small ubiquitin-like modifier)-1 and SUMO-3. Three SUMOylation sites, K75, K250, and K254, were mapped on the shared N-terminal region of these molecules, while a fourth site, K364, was identified in the C-terminal part exclusive of LEDGF/p75. The N-terminal SUMO targets are located in evolutionarily conserved charge-rich regions that lack resemblance to the described consensus SUMOylation motif, whereas the C-terminal SUMO target is solvent exposed and situated in a typical consensus motif. SUMOylation did not affect the cellular localization of LEDGF proteins and was not necessary for their chromatin-binding ability, nor did it affect this activity. However, lysine to arginine mutations of the identified SUMO acceptor sites drastically inhibited LEDGF SUMOylation, extended the half-life of LEDGF/p75, and significantly increased its transcriptional activity on the heat shock protein 27 promoter, indicating a negative effect of SUMOylation on the transcriptional activity of LEDGF/p75. Considering that SUMOylation is known to negatively affect the transcriptional activity of all transcription factors known to transactivate heat shock protein 27 expression, these findings support the paradigm establishing SUMOylation as a global neutralizer of cellular processes upregulated upon cellular stress.
AB - Lens epithelium-derived growth factor (LEDGF) proteins p75 and p52 are transcriptional coactivators that connect sequence-specific activators to the basal transcription machinery. We have found that these proteins are posttranslationally modified by SUMO (small ubiquitin-like modifier)-1 and SUMO-3. Three SUMOylation sites, K75, K250, and K254, were mapped on the shared N-terminal region of these molecules, while a fourth site, K364, was identified in the C-terminal part exclusive of LEDGF/p75. The N-terminal SUMO targets are located in evolutionarily conserved charge-rich regions that lack resemblance to the described consensus SUMOylation motif, whereas the C-terminal SUMO target is solvent exposed and situated in a typical consensus motif. SUMOylation did not affect the cellular localization of LEDGF proteins and was not necessary for their chromatin-binding ability, nor did it affect this activity. However, lysine to arginine mutations of the identified SUMO acceptor sites drastically inhibited LEDGF SUMOylation, extended the half-life of LEDGF/p75, and significantly increased its transcriptional activity on the heat shock protein 27 promoter, indicating a negative effect of SUMOylation on the transcriptional activity of LEDGF/p75. Considering that SUMOylation is known to negatively affect the transcriptional activity of all transcription factors known to transactivate heat shock protein 27 expression, these findings support the paradigm establishing SUMOylation as a global neutralizer of cellular processes upregulated upon cellular stress.
KW - Heat shock protein 27 promoter
KW - Lens epithelium-derived growth factor
KW - Posttranslational modifications
KW - Small ubiquitin-like modifier
KW - Transcriptional regulation
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U2 - 10.1016/j.jmb.2010.03.063
DO - 10.1016/j.jmb.2010.03.063
M3 - Article
C2 - 20382164
AN - SCOPUS:77953083330
SN - 0022-2836
VL - 399
SP - 221
EP - 239
JO - Journal of Molecular Biology
JF - Journal of Molecular Biology
IS - 2
ER -