TY - JOUR
T1 - Mutations in ERK2 binding sites affect nuclear entry
AU - Yazicioglu, Mustafa N.
AU - Goad, Daryl L.
AU - Ranganathan, Aarati
AU - Whitehurst, Angelique W.
AU - Goldsmith, Elizabeth J.
AU - Cobb, Melanie H.
PY - 2007/9/28
Y1 - 2007/9/28
N2 - The MAPK ERK2 can enter and exit the nucleus by an energy-independent process that is facilitated by direct interactions with nuclear pore proteins. Several studies also suggest that the localization of ERK2 can be influenced by carrier proteins. Using import reconstitution assays, we examined a group of ERK2 mutants defective in known protein interactions to determine structural properties of ERK2 that contribute to its nuclear entry. ERK2 mutants defective in binding to substrates near the active site or to basic/hydrophobic docking (D) motifs were imported normally. Several ERK2 mutants defective in interactions with FXF motifs displayed slowed rates of nuclear import. The import-impaired mutants also showed reduced binding to a recombinant C-terminal fragment of nucleoporin 153 that is rich in FXF motifs. Despite the deficit revealed in some mutants via reconstitution assays, all but one of the ERK2 mutants accumulated in nuclei of stimulated cells in a manner comparable with the wild type protein; the mutant most defective in import remained in the cytoplasm. These results further support the idea that direct interactions with nucleoporins are involved in ERK2 nuclear entry and that multiple events contribute to the ligand-dependent relocalization of these protein kinases.
AB - The MAPK ERK2 can enter and exit the nucleus by an energy-independent process that is facilitated by direct interactions with nuclear pore proteins. Several studies also suggest that the localization of ERK2 can be influenced by carrier proteins. Using import reconstitution assays, we examined a group of ERK2 mutants defective in known protein interactions to determine structural properties of ERK2 that contribute to its nuclear entry. ERK2 mutants defective in binding to substrates near the active site or to basic/hydrophobic docking (D) motifs were imported normally. Several ERK2 mutants defective in interactions with FXF motifs displayed slowed rates of nuclear import. The import-impaired mutants also showed reduced binding to a recombinant C-terminal fragment of nucleoporin 153 that is rich in FXF motifs. Despite the deficit revealed in some mutants via reconstitution assays, all but one of the ERK2 mutants accumulated in nuclei of stimulated cells in a manner comparable with the wild type protein; the mutant most defective in import remained in the cytoplasm. These results further support the idea that direct interactions with nucleoporins are involved in ERK2 nuclear entry and that multiple events contribute to the ligand-dependent relocalization of these protein kinases.
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U2 - 10.1074/jbc.M703460200
DO - 10.1074/jbc.M703460200
M3 - Article
C2 - 17656361
AN - SCOPUS:35348957232
SN - 0021-9258
VL - 282
SP - 28759
EP - 28767
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 39
ER -