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Molecular basis for the substrate specificity of plant guanine nucleotide exchange factors for ROP
Author(s) -
Fricke Inka,
Berken Antje
Publication year - 2009
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2008.12.008
Subject(s) - guanine nucleotide exchange factor , guanine , chemistry , nucleotide , biochemistry , substrate (aquarium) , biology , gene , gtpase , ecology
Plant G proteins of the ROP/RAC family regulate cellular processes including cytoskeletal rearrangement in polar growth. Activation of the ROP molecular switch is triggered by guanine nucleotide exchange factors. Plant‐specific RopGEFs are exclusively active on ROPs despite their high homology to animal Rho proteins. Based on a sequence comparison of ROPs vs. animal Rho proteins together with structural data on distinct ROPs, we identified unique substrate determinants of RopGEF specificity by mutational analysis: asparagine 68 next to switch II, arginine 76 of a putative phosphorylation motif and the Rho insert are essential for substrate recognition by RopGEFs. These data also provide first evidence for a function of the Rho insert in interactions with GEFs.