The arginine residue at position 38 of PIK3CA (R38) is located at a contact site between the ABD and kinase domains of PIK3CA. Substitution of this arginine residue with cysteine in PIK3CA R38C mutant is likely to disrupt the interaction between the ABD domain and the kinase domain, causing a confomrational change of the kinase domain that leads to increased enzymatic activity (Huang et al. 2007).
The arginine residue at position 38 of PIK3CA (R38) is located at a contact site between the ABD and kinase domains of PIK3CA. Substitution of this arginine residue with glycine in PIK3CA R38G mutant is likely to disrupt the interaction between the ABD domain and the kinase domain, causing a confomrational change of the kinase domain that leads to increased enzymatic activity (Huang et al. 2007).
The arginine residue at position 38 of PIK3CA (R38) is located at a contact site between the ABD and kinase domains of PIK3CA. Substitution of this arginine residue with serine in PIK3CA R38S mutant is likely to disrupt the interaction between the ABD domain and the kinase domain, causing a confomrational change of the kinase domain that leads to increased enzymatic activity (Huang et al. 2007).
The arginine residue at position 38 of PIK3CA (R38) is located at a contact site between the ABD and kinase domains of PIK3CA. Substitution of this arginine residue with histidine in PIK3CA R38H mutant is likely to disrupt the interaction between the ABD domain and the kinase domain, causing a confomrational change of the kinase domain that leads to increased enzymatic activity (Huang et al. 2007). PIK3CA R38H mutant shows reduced PIK3R1 binding and modestly increased catalytic activity (measured indirectly, via AKT1 phosphorylation) under serum starved conditions (Zhao et al. 2005).
Based on structural and functional studies of PIK3CA E542K mutant (Miled et al. 2007), substitution of glutamic acid residue at position 542 of PIK3CA with glutamine is expected to disrupt inhibitory interaction between the helical domain of PIK3CA and the nSH2 domain of PIK3R1, resulting in constitutive activity of the PI3K complex containing PIK3CA E542Q mutant.
Based on structural and functional studies of PIK3CA Q546K mutant (Miled et al. 2007), substitution of glutamine residue at position 546 of PIK3CA with proline is expected to disrupt inhibitory interaction between the helical domain of PIK3CA and the nSH2 domain of PIK3R1, resulting in constitutive activity of the PI3K complex containing PIK3CA Q546P mutant.
Based on structural and functional studies of PIK3CA Q546K mutant (Miled et al. 2007), substitution of glutamine residue at position 546 of PIK3CA with arginine is expected to disrupt inhibitory interaction between the helical domain of PIK3CA and the nSH2 domain of PIK3R1, resulting in constitutive activity of the PI3K complex containing PIK3CA Q546R mutant.
Based on structural and functional studies of PIK3CA Q546K mutant (Miled et al. 2007), substitution of glutamine residue at position 546 of PIK3CA with histidine is expected to disrupt inhibitory interaction between the helical domain of PIK3CA and the nSH2 domain of PIK3R1, resulting in constitutive activity of the PI3K complex containing PIK3CA Q546H mutant.
Based on structural and functional studies of the PIK3CA E545K mutant (Miled et al. 2007, Huang et al. 2007, Zhao et al. 2005), the substitution of glutamic acid residue at position 545 of PIK3CA with glycine is expected to disrupt inhibitory interaction between the helical domain of PIK3CA and the nSH2 domain of PIK3R1 and result in the constitutive activity of the PI3K complex containing PIK3CA E545G mutant.
Based on structural and functional studies of PIK3CA Q546L mutant (Miled et al. 2007), substitution of glutamine residue at position 546 of PIK3CA with leucine is expected to disrupt inhibitory interaction between the helical domain of PIK3CA and the nSH2 domain of PIK3R1, resulting in constitutive activity of the PI3K complex containing PIK3CA Q546L mutant.
Based on structural and functional studies of PIK3CA E542K mutant (Miled et al. 2007), substitution of glutamic acid residue at position 542 of PIK3CA with valine is expected to disrupt inhibitory interaction between the helical domain of PIK3CA and the nSH2 domain of PIK3R1, resulting in constitutive activity of the PI3K complex containing PIK3CA E542V mutant.
Based on structural and functional studies of the PIK3CA E545K mutant (Miled et al. 2007, Huang et al. 2007, Zhao et al. 2005), the substitution of glutamic acid residue at position 545 of PIK3CA with valine is expected to disrupt inhibitory interaction between the helical domain of PIK3CA and the nSH2 domain of PIK3R1 and result in the constitutive activity of the PI3K complex containing PIK3CA E545V mutant.
Based on structural and functional studies of PIK3CA Q546K mutant (Miled et al. 2007), substitution of glutamine residue at position 546 of PIK3CA with glutamic acid is expected to disrupt inhibitory interaction between the helical domain of PIK3CA and the nSH2 domain of PIK3R1, resulting in constitutive activity of the PI3K complex containing PIK3CA Q546E mutant.
Based on structural and functional studies of the PIK3CA E545K mutant (Miled et al. 2007, Huang et al. 2007, Zhao et al. 2005), the substitution of glutamic acid residue at position 545 of PIK3CA with glutamine is expected to disrupt inhibitory interaction between the helical domain of PIK3CA and the nSH2 domain of PIK3R1 and result in the constitutive activity of the PI3K complex containing PIK3CA E545Q mutant.
Substitution of glutamic acid residue at position 545 of PIK3CA with lysine disrupts inhibitory interaction between the helical domain of PIK3CA and the nSH2 domain of PIK3R1. The PI3K complex containing PIK3CA E545K mutant is constitutively active under serum starved conditions (Miled et al. 2007, Huang et al. 2007, Zhao et al. 2005).
Similar to PIK3CA E545K mutant (Miled et al. 2007, Huang et al. 2007, Zhao et al. 2005), PIK3CA E545A mutant is constitutively active in the absence of growth factors (Horn et al. 2008). The underlying mechanism for oncogenic activation is likely to be identical - the substitution of glutamic acid residue at position 545 of PIK3CA with alanine is expected to disrupt inhibitory interaction between the helical domain of PIK3CA and the nSH2 domain of PIK3R1.
Substitution of glutamine residue at position 546 of PIK3CA with lysine disrupts inhibitory interaction between the helical domain of PIK3CA and the nSH2 domain of PIK3R1. The PI3K complex containing PIK3CA Q546K mutant is constitutively active (Miled et al. 2007).
Substitution of glutamic acid residue at position 542 of PIK3CA with lysine disrupts inhibitory interaction between the helical domain of PIK3CA and the nSH2 domain of PIK3R1. The PI3K complex containing PIK3CA E542K mutant is constitutively active (Miled et al. 2007, Horn et al. 2008).
Substitution of histidine residue with tyrosine at position 1047 in the kinase domain of PIK3CA is predicted, based on PIK3CA crystal structure, to change the conformation of the activation loop (Huang et al. 2007).
Substitution of methionine residue with valine at position 1043 in the kinase domain of PIK3CA is predicted, based on PIK3CA crystal structure, to change the conformation of the activation loop (Huang et al. 2007).
Substitution of methionine residue with threonine at position 1043 in the kinase domain of PIK3CA is predicted, based on PIK3CA crystal structure, to change the conformation of the activation loop (Huang et al. 2007).
Substitution of methionine residue with isoleucine at position 1043 in the kinase domain of PIK3CA is predicted, based on PIK3CA crystal structure, to change the conformation of the activation loop (Huang et al. 2007). The PI3K complex containing PIK3CA M1043I mutant is constitutively active, but its activity may be additional boosted by binding of PIK3R1 regulatory subunit to phosphopeptides generated by activated receptor tyrosine kinases (Hon et al. 2011).
Substitution of histidine residue with arginine at position 1047 in the kinase domain of PIK3CA is predicted, based on PIK3CA crystal structure, to change the conformation of the activation loop (Huang et al. 2007). The PI3K complex containing PIK3CA H1047R mutant is constitutively active, in the absence of growth factors (Zhao et al. 2005, Horn et al. 2008), but its activity may be additional boosted by binding of PIK3R1 regulatory subunit to phosphopeptides generated by activated receptor tyrosine kinases (Hon et al. 2011).
Substitution of histidine residue with leucine at position 1047 in the kinase domain of PIK3CA is predicted, based on PIK3CA crystal structure, to change the conformation of the activation loop (Huang et al. 2007). The PI3K complex containing PIK3CA H1047L mutant is constitutively active, but its activity may be additional boosted by binding of PIK3R1 regulatory subunit to phosphopeptides generated by activated receptor tyrosine kinases (Hon et al. 2011).