TY - JOUR
T1 - A ubiquitin-interacting motif from Hrs binds to and occludes the ubiquitin surface necessary for polyubiquitination in monoubiquitinated proteins
AU - Shekhtman, Alexander
AU - Cowburn, David
N1 - Funding Information:
This work was supported by NIH Grant GM 47021 and NCI Fellowship F037244.
PY - 2002
Y1 - 2002
N2 - The ubiquitin-interacting motif (UIM) is a short, approximately 20 residue, structural element, which is present in, but not limited to, the proteins involved in endocytotic and proteasomal degradation. UIMs facilitate endocytotic vesicular sorting of the monoubiquitinated proteins and may be important for the targeting of the polyubiquitinated proteins to the proteasome. Using heteronuclear NMR backbone and side-chain chemical shift mapping of the ubiquitin interaction surface, the UIM from the hepatocyte growth factor-regulated tyrosine kinase substrate, Hrs, specifically binds to the ubiquitin hydrophobic surface using UIM's well-conserved central helical LALAL motif. Molecular modeling of the ubiquitin:UIM_Hrs complex suggests that binding occurs through a specific interaction of Leu263 and Leu267 of the UIM_Hrs with two ubiquitin hydrophobic patches located in close proximity to the ubiquitin major polyubiquitination site, Lys48. Intramolecular binding of ubiquitin to a UIM in monoubiquitinated proteins would render Lys48 unavailable for further ubiquitination, thus, explaining the absolute requirement of UIMs for monoubiquitination. Two leucines, Leu265 and Leu269, located on the opposite face of UIM_Hrs can also interact, albeit less favorably than Leu263 and Leu267, with the ubiquitin hydrophobic patches, suggesting a possible mode for polyubiquitin:UIM binding and apparent preference of UIMs for polyubiquitins.
AB - The ubiquitin-interacting motif (UIM) is a short, approximately 20 residue, structural element, which is present in, but not limited to, the proteins involved in endocytotic and proteasomal degradation. UIMs facilitate endocytotic vesicular sorting of the monoubiquitinated proteins and may be important for the targeting of the polyubiquitinated proteins to the proteasome. Using heteronuclear NMR backbone and side-chain chemical shift mapping of the ubiquitin interaction surface, the UIM from the hepatocyte growth factor-regulated tyrosine kinase substrate, Hrs, specifically binds to the ubiquitin hydrophobic surface using UIM's well-conserved central helical LALAL motif. Molecular modeling of the ubiquitin:UIM_Hrs complex suggests that binding occurs through a specific interaction of Leu263 and Leu267 of the UIM_Hrs with two ubiquitin hydrophobic patches located in close proximity to the ubiquitin major polyubiquitination site, Lys48. Intramolecular binding of ubiquitin to a UIM in monoubiquitinated proteins would render Lys48 unavailable for further ubiquitination, thus, explaining the absolute requirement of UIMs for monoubiquitination. Two leucines, Leu265 and Leu269, located on the opposite face of UIM_Hrs can also interact, albeit less favorably than Leu263 and Leu267, with the ubiquitin hydrophobic patches, suggesting a possible mode for polyubiquitin:UIM binding and apparent preference of UIMs for polyubiquitins.
KW - Endocytosis
KW - Hrs
KW - Monoubiquitination
KW - NMR chemical shift mapping
KW - Proteasome
KW - Ubiquitin
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U2 - 10.1016/S0006-291X(02)02006-5
DO - 10.1016/S0006-291X(02)02006-5
M3 - Article
C2 - 12207904
AN - SCOPUS:0036392305
SN - 0006-291X
VL - 296
SP - 1222
EP - 1227
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 5
ER -