Abstract: The present invention relates generally to PHLPP, a novel phosphatase that inactivates Akt (protein kinase B) by directly dephosphorylating the hydrophobic domain of the C-terminus. More specifically, the invention relates to PHLPP polynucleotides and the polypeptides encoded by these polynucleotides and the use of these polynucleotides and polypeptides in the treatment and diagnosis of biological conditions mediated by Akt phosphorylation, particularly cancer. This invention relates to PHLPP polynucleotides and polypeptides as well as vectors, host cells, antibodies directed to PHLPP polynucleotides and polypeptides and recombinant and synthetic methods for producing the same. The invention further relates to screening methods for identifying agonists and antagonists of PHLPP polynucleotides and polypeptides of the invention.

Abstract: A chimeric phosphorylation indicator (CPI) as provided herein can contain a donor molecule, a phosphorylatable domain, a phosphoaminoacid binding domain (PAABD), and an acceptor molecule. Where the phosphorylatable domain is phosphorylatable by protein kinase C (PKC), the CPI is a c-kinase activity reporter (CKAR). Donor and acceptor molecules may be, independently, fluorescent proteins such as non-oligomerizing fluorescent proteins. A CPI can contain a phosphorylatable polypeptide and a fluorescent protein; the phosphorylatable polypeptide may be contained within the sequence of the fluorescent protein, or the fluorescent protein may be contained within the sequence of the phosphorylatable polypeptide. The spatiotemporal properties of the PKC signal pathway may be tested with CKAR, calcium-sensing fluorophores and FRET-based translocation assays. Polynucleotides encoding such CPIs, and kits containing the indicators and/or the polynucleotides, are provided.