Over several decades of cancer research, T antigen, a.k.a MAMU, has proven itself to be a strong activator of cellular transformation. In a stunning finding revealed by Tushar Gupta and colleagues (in a recent Journal of Virology paper), SV40 T antigen declares that it does not need activator E2Fs to cause cellular transformation. T antigen said, “I have been telling you all along. I don’t need no activator E2Fs!”
Ping An (+ et al.) has recently published a paper that describes the core and distinct enzymatic activities of the Zn-ATPase domain of T antigen from 3 polyomaviruses. Check it out…the results may surprise you. Congratulations Ping!
Polyomavirus T antigens! Nicholas Giacobbi et al. show, in their new Virology paper, that T antigen from SV40 and two human polyomaviruses, BKV and JCV, have the ability to induce an antiviral state in mouse embryonic fibroblasts. Additionally, they show that the antiviral state requires STAT1 expression. Chalk up another activity for the MAMU!
The current model for tumorigenesis is that mutations in genes alter gene expression and/or the normal function of proteins or gene expression. Correspondingly, this predicts that an oncogene such as T antigen would have the same effects in different cell types. However, experiments performed by Mayte Saenz-Robles and colleagues challenge this prediction. In a paper published in Molecular Cancer Research, they describe how a truncated form of T antigen (aka MAMU) called N136 is able to form adenomatous polyps in the digestive tract when expressed in progenitor crypt cells while only causing hyperplasia and dysplasia in the villi. Isn’t cell-type specificity cool?!
This paper describes the effect of polyomavirus T antigens on CBP/p300, and suggests that the T antigens use additional mechanisms in the transformation and immortalization of cells. Congratulations to Mayte Saenz-Robles and all the authors!
Ping An, Mayte Saenz-Robles and Jim Pipas have recently published a new review in Annual Reviews in Microbiology. The review discusses the amazing molecular machines of the T antigens of polyomaviruses. You can read the paper here.
Graduate students Nicole Seneca and Tushar Gupta will be giving a talk on their current research at the DNA Tumour Virus Meeting in Montreal, Canada on July 16 – 21st. Nicole’s talk is titled “The Variable Host Range Region of BK and JC Polyomavirus T-Antigens, But Not SV40 T-Antigen, Suppresses Transformation in MEFs” and Tushar’s talk is “Role of activator E2Fs in SV40 large T antigen mediated proliferation and transformation.”