We have pioneered the use of a genetic kinase ‘knockin’ strategy in which a single point-mutation in the mouse germline creates an inactive PI3K (reviewed by us in ). To the best of our knowledge, the PI3K delta isoform of PI3K was the first kinase subjected to this type of genetic modification in mice . Similar to small molecule inhibitors, this approach does not affect the expression of the PI3K protein and thus more closely models the use of a PI3K drug at the organismal level than gene knock-out strategies.
Using this knockin strategy, we have uncovered physiological roles of the PI3K alpha [3, 4], p110beta [5, 6] and PI3K delta [2, 7] isoforms of PI3K. We have also employed the same strategy to target class II  and III PI3Ks and are currently in the process of characterising these mice and cells thereof.
- Vanhaesebroeck, B., et al., Signalling by PI3K isoforms: insights from gene-targeted mice. Trends Biochem Sci, 2005. 30(4): p. 194-204.
- Okkenhaug, K., et al., Impaired B and T cell antigen receptor signaling in p110delta PI 3-kinase mutant mice. Science, 2002. 297(5583): p. 1031-4.
- Foukas, L.C., et al., Critical role for the p110alpha phosphoinositide-3-OH kinase in growth and metabolic regulation. Nature, 2006. 441(7091): p. 366-70.
- Graupera, M., et al., Angiogenesis selectively requires the p110alpha isoform of PI3K to control endothelial cell migration. Nature, 2008. 453(7195): p. 662-6.
- Guillermet-Guibert, J., et al., The p110beta isoform of phosphoinositide 3-kinase signals downstream of G protein-coupled receptors and is functionally redundant with p110gamma. Proc Natl Acad Sci U S A, 2008. 105(24): p. 8292-7.
- Kulkarni, S., et al., PI3Kbeta plays a critical role in neutrophil activation by immune complexes. Sci Signal, 2011. 4(168): p. ra23.
- Ali, K., et al., Essential role for the p110delta phosphoinositide 3-kinase in the allergic response. Nature, 2004. 431(7011): p. 1007-11.
- Alliouachene, S., et al., Inactivation of the Class II PI3K-C2β Potentiates Insulin Signaling and Sensitivity. Cell Rep, 2015. 13(9): p. 14.