Interaction of the Mason-Pfizer monkey virus matrix protein and its budding deficient mutants with the plasma membrane

Tomáš Kroupa1,2, Jan Prchal2, Tomáš Ruml1, Richard Hrabal2

1Department of Biochemistry and Microbiology, University of Chemistry and Technology, Technická 5, 166 28 Prague 6, Czech Republic

2Laboratory of NMR Spectroscopy, University of Chemistry and Technology, Technická 5, 166 28 Prague 6, Czech Republic

tomas.kroupa@vscht.cz

 

Mason-Pfizer monkey virus (M-PMV) is a simple Betaretrovirus and is often used as a model organism for studying the late phase of the retroviral life cycle because the formation of the immature viral particle and budding are spatially separated. Retroviral matrix proteins play a key role in the transport of viral precursor proteins inside the cell and in their interactions with cellular membrane which is an important prerequisite for the final step in the viral budding and maturation.

We have studied the interactions of the M-PMV wild-type MA and its two budding deficient mutants (T41I/T78I and Y28F/Y67F) with water soluble phospholipids with shorter fatty acid residues and liposomes consisted of phospholipids with naturally long fatty acid chains. The interactions were monitored by several experimental techniques, such as liposomes pelleting assays, NMR spectroscopy and MicroScale Thermophoresis. We found that the affinity of M-PMV MA proteins to both water soluble phospholipids and liposomes is much lower than in HIV-1 MA and therefore, the conclusion is that M-PMV might adopt a different membrane binding mechanism than HIV-1.