TY - JOUR
T1 - Inhibition of DNA binding by differential sumoylation of heat shock factors
AU - Anckar, Julius
AU - Hietakangas, Ville
AU - Denessiouk, Konstantin
AU - Thiele, Dennis J
AU - Johnson, Mark S
AU - Sistonen, Lea
PY - 2006/2
Y1 - 2006/2
N2 - Covalent modification of proteins by the small ubiquitin-related modifier SUMO regulates diverse biological functions. Sumoylation usually requires a consensus tetrapeptide, through which the binding of the SUMO-conjugating enzyme Ubc9 to the target protein is directed. However, additional specificity determinants are in many cases required. To gain insights into SUMO substrate selection, we have utilized the differential sumoylation of highly similar loop structures within the DNA-binding domains of heat shock transcription factor 1 (HSF1) and HSF2. Site-specific mutagenesis in combination with molecular modeling revealed that the sumoylation specificity is determined by several amino acids near the consensus site, which are likely to present the SUMO consensus motif to Ubc9. Importantly, we also demonstrate that sumoylation of the HSF2 loop impedes HSF2 DNA-binding activity, without affecting its oligomerization. Hence, SUMO modification of the HSF2 loop contributes to HSF-specific regulation of DNA binding and broadens the concept of sumoylation in the negative regulation of gene expression.
AB - Covalent modification of proteins by the small ubiquitin-related modifier SUMO regulates diverse biological functions. Sumoylation usually requires a consensus tetrapeptide, through which the binding of the SUMO-conjugating enzyme Ubc9 to the target protein is directed. However, additional specificity determinants are in many cases required. To gain insights into SUMO substrate selection, we have utilized the differential sumoylation of highly similar loop structures within the DNA-binding domains of heat shock transcription factor 1 (HSF1) and HSF2. Site-specific mutagenesis in combination with molecular modeling revealed that the sumoylation specificity is determined by several amino acids near the consensus site, which are likely to present the SUMO consensus motif to Ubc9. Importantly, we also demonstrate that sumoylation of the HSF2 loop impedes HSF2 DNA-binding activity, without affecting its oligomerization. Hence, SUMO modification of the HSF2 loop contributes to HSF-specific regulation of DNA binding and broadens the concept of sumoylation in the negative regulation of gene expression.
KW - Amino Acid Sequence
KW - Animals
KW - COS Cells
KW - Chlorocebus aethiops
KW - Conserved Sequence
KW - DNA/metabolism
KW - DNA-Binding Proteins/genetics
KW - Heat Shock Transcription Factors
KW - Heat-Shock Proteins/genetics
KW - Humans
KW - Mice
KW - Molecular Sequence Data
KW - Protein Processing, Post-Translational
KW - Small Ubiquitin-Related Modifier Proteins/metabolism
KW - Transcription Factors/genetics
KW - Transfection
KW - Ubiquitin-Conjugating Enzymes/metabolism
U2 - 10.1128/MCB.26.3.955-964.2006
DO - 10.1128/MCB.26.3.955-964.2006
M3 - Article
C2 - 16428449
SN - 0270-7306
VL - 26
SP - 955
EP - 964
JO - Molecular and Cellular Biology
JF - Molecular and Cellular Biology
IS - 3
ER -