Dr. Jerry LaRue
Worldwide, more than 38 million people are living with human immunodeficiency virus (HIV), about 84 million people have become infected with HIV since the start of the epidemic, and 40.1 million of those diagnoses led to death. HIV Type-1 is the most common type of HIV, attacking the body’s immune system by destroying CD4 cells. The virus attaches itself to the CD4 cell, taking control of its DNA and replicating itself to release more HIV into the bloodstream. The Gag proteins of HIV-1 are crucial players in the virus’ assembly, release, and maturation; it utilizes its essential matrix protein (MA) to target the plasma membrane, allowing the virus to continue its replication cycle. Calmodulin (CaM) is a calcium-sensing protein that acts as a regulator molecule in many cellular functions. When calmodulin is bound to the HIV-1 matrix protein, two alpha helices form instead of the typical one, which has yet to be fully understood. Current research has suggested that in the binding between HIV-1 MA and CaM, the myristyl group within the MA becomes exposed and anchors down to the plasma membrane. CaM has been shown to be upregulated in the presence of HIV infections, and this rise is correlated to the increased accessibility of the MA’s binding sites. The matrix protein also contains tryptophan –– a fluorescent compound that varies in intensity based on conformation type –– which can be observed through fluorescence spectroscopy and anisotropy techniques. These binding effects are hypothesized to facilitate increased viral production of HIV-1, implying that the hindering of the matrix protein binding site could lead to reduced viral replication. This project aims to examine and analyze these interactions between HIV-MA and CaM in the presence and absence of calcium using fluorescence spectroscopy.
Karimi, Nousha; Valdez, Fabian; Mau, Davis; and Sakamaki, K., "Analyzing Conformational Changes in the Binding of HIV-1 Matrix Protein, N and C Terminals, to Calmodulin" (2023). Student Scholar Symposium Abstracts and Posters. 582.