Related Experiment Video
Updated: Aug 10, 2026

Imaging of HIV-1 Envelope-induced Virological Synapse and Signaling on Synthetic Lipid Bilayers
Published on: March 8, 2012
Second messengers induced by the envelope protein of a retrovirus
1Department of Biological Sciences, University of South Carolina, Columbia 29208, USA. Bolander@Biol.SC.Edu
Abstract:
The envelope protein (gp52) of the mouse mammary tumor virus (MMTV) can stimulate RNA synthesis via binding to its cellular receptor on mammary epithelium. This effect was mimicked by either nitric oxide (NO) or 8-bromo-cGMP and was blocked by an NO inhibitor. Furthermore, the effects of gp52 and 8-bromo-cGMP were not additive at maximal concentrations, suggesting that they were using the same signaling route. Finally, gp52 elevated cGMP levels in mammary epithelium. These data suggest that gp52 activates the following transduction pathway in this tissue: gp52-->NO synthase-->NO-->soluble guanylate cyclase cGMP RNA synthesis. In contrast to the mammary gland, gp52 inhibited RNA synthesis in the diaphragm. However, the effect was again mimicked by NO, blocked by an NO inhibitor, and the effects of gp52 and NO were not additive. Therefore, it appears that gp52 is using the NO-cGMP pathway in both tissues, but that muscle tissue may be more susceptible to the toxic effects of NO.
Related Concept Videos
What are Second Messengers?
Retrovirus Life Cycles
Retroviruses
Intralumenal Vesicles and Multivesicular Bodies
Mechanisms of Retrovirus-induced Cancers
Amplifying Signals via Second Messengers

