Adaptor Protein Phosphotyrosine Interaction PH Domain And leucine Zipper Containing Protein 1 (APPL1)

APPL1 has been shown to be involved in the regulation of cell proliferation, and in the crosstalk between the adiponectin signalling and insulin signalling pathways. The encoded protein binds many other proteins, including RAB5A, DCC, AKT2, PIK3CA, adiponectin receptors, and proteins of the NuRD/MeCP1 complex. This protein is found associated with endosomal membranes, but can be released by EGF and translocated to the nucleus. The PH domain of APPL shows similarity to those found in GTPase-activating proteins such as oligophrenin-1, whereas its PTB domain exhibits homology with CED-6, an adaptor protein that promotes engulfment of apoptotic cells, and IB1, a transactivator of the GLUT2 gene. APPL is highly expressed in skeletal muscle, heart, ovary, and pancreas, tissues in which AKT2 mRNA is abundant.