Remote hot spots mediate protein substrate recognition for the Cdc25 phosphatase.
Cdc25B is a phosphatase that catalyzes the dephosphorylation and activation of the cyclin-dependent kinases, thus driving cell cycle progression. We have identified two residues, R488 and Y497, located >20 A from the active site, that mediate protein substrate recognition without affecting activity toward small-molecule substrates. Injection of Cdc25B wild-type but not the R488L or Y497A variants induces germinal vesicle breakdown and cyclin-dependent kinase activation in Xenopus oocytes. The conditional knockout of the cdc25 homolog (mih1) in Saccharomyces cerevisiae can be complemented by the wild type but not by the hot spot variants, indicating that protein substrate recognition by the Cdc25 phosphatases is an essential and evolutionarily conserved feature.
Sohn
J
J
Departments of Biochemistry and Chemistry, Duke University Medical Center, Durham, NC 27710, USA.
Kristjánsdóttir
K
K
Safi
A
A
Parker
B
B
Kiburz
B
B
Rudolph
J
J
D000818:Animals; D001665:Binding Sites / Q000235:genetics; D005260:Female; D005800:Genes, Fungal; D005816:Genetic Complementation Test; D066298:In Vitro Techniques; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D009865:Oocytes / Q000378:metabolism; D011487:Protein Conformation; D017027:Protein Tyrosine Phosphatases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013379:Substrate Specificity; D014982:Xenopus laevis; D020687:cdc25 Phosphatases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D020666:ras-GRF1
C542351:CDC25 protein, S cerevisiae; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; D020666:ras-GRF1; D017027:Protein Tyrosine Phosphatases; D020687:cdc25 Phosphatases