Amplifying Btk's signal.
The Tec kinase Btk is an important regulator of antigen receptor activation of phospholipase C-gamma (PLC-gamma). Data from Carpenter and colleagues (Saito et al., this issue of Immunity) now suggest that Btk also activates phosphatidylinositol-4-phosphate 5-kinase (PIP5K), thereby stimulating a positive feedback loop that generates PI(4,5)P2, the substrate for both phosphoinositide 3-kinase (PI3K) and PLC-gamma.
Schwartzberg
Pamela L
PL
National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA.
D000077329:Agammaglobulinaemia Tyrosine Kinase; D000818:Animals; D002118:Calcium / Q000378:metabolism; D005246:Feedback; D006801:Humans; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D015398:Signal Transduction; D013379:Substrate Specificity
D017853:Phosphotransferases (Alcohol Group Acceptor); C020077:1-phosphatidylinositol-4-phosphate 5-kinase; D011505:Protein-Tyrosine Kinases; D000077329:Agammaglobulinaemia Tyrosine Kinase; C000625949:BTK protein, human; D002118:Calcium