Experimental Ad36 infection of mice improves hyperglycemia, despite a 60% fat diet and without reducing adiposity. Signaling studies suggest that in these mice, Ad36 improves glycemic control by increasing glucose uptake by BAY 43-9006 adipose tissue and skeletal muscle and by reducing hepatic glucose output. Mechanistic in vitro studies show that Ad36 increases insulin independent glucose uptake in diabetic and non-diabetic human adipose tissue explants and in human primary muscle cell culture in a dose dependent Vemurafenib manner. Ad36 requires Ras mediated activation of phosphatidyl inositol 3-kinase , to increase cellular glucose uptake. Collectively, these data reveal anti-hyperglycemic properties of Ad36,that are clinically relevant to humans, and offer a tool to develop new anti-diabetic agents. Harnessing certain properties of viruses for beneficial purposes has been creatively used for several years. For example, anti-bacterial properties of bacteriophage virus , the oncolytic ability of a mutant adenovirus , or the use of Herpes simplex virus and several other viruses for lysing cancer cells , have been used alone, or with various synergistic drugs. Clearly, infection with Ad36 is not a viable treatment option. Instead, identifying the viral protein responsible for Ad36- induced glucose disposal is the next step in harnessing the antihyperglycemic potential of the virus for therapeutic purpose. Adenoviruses have a set of several early genes that encode proteins for evading the host immune system and changing cell function for favorable viral replication, and several late genes, that encode structural proteins required for viral particle assembly. This study identified the Ad36 gene that mediates the glucose disposal induced by the virus. Considering that Ad36 requires Ras/PI3K pathway for enhancing glucose uptake , we focused on E4orf1 gene of the virus that up-regulates this pathway. The E4orf1 gene of Ad36 is transcribed from the first open reading frame of Ad36 early gene 4, and yields a 17 kDa, 125 amino acid protein, and has a PBM through which it interacts with other proteins containing PDZ regions for scaffolding. E4orf1 is necessary and sufficient for Ad36 to activate the PI3K pathway , and its PBM is required for the effect. E4orf1 protein of Ad9, a closely related adenovirus, stimulates Ras-mediated PI3K activation , via the interaction of its PBM with Dlg1 protein. In Ad36 infected animals, E4orf1 is expressed in adipose tissue or livers , and its expression in the liver positively correlates with glycemic improvement in mice. This background provided the rationale to test the role of E4orf1 as the mediator of Ad36-induced glucose uptake, as outlined below.