Disease relevance of M1

• Matrix protein (M1) of influenza virus is a bifunctional protein that mediates the encapsidation of RNA-nucleoprotein cores into the membrane envelope [1].
• The morphology and composition of influenza A virus particles are not affected by low levels of M1 and M2 proteins in infected cells [2].
• In order to elucidate the functions of these proteins in virus assembly we have expressed NP and M1 in BHK-21 cells using Semliki Forest virus replicons and analysed their molecular interactions [3].
• Full-length M1, the N-terminal domain, and the C-terminal part of M1 (residues 165--252) were produced in Escherichia coli [4].

High impact information on M1

• Structure of a bifunctional membrane-RNA binding protein, influenza virus matrix protein M1 [1].
• We generated a recombinant influenza A virus (Mmut) that produced low levels of matrix (M1) and M2 proteins in infected cells [2].
• We propose that a threshold amount of M1 protein is needed for the assembly of viral components into an infectious particle and that budding is delayed in Mmut virus-infected cells until sufficient levels of M1 protein accumulate at the plasma membrane [2].
• The plasmids also contained the CMV promoter, which permitted expression of M1, NP, and vRNA in Madin-Darby canine kidney (MDCK) [5].
• We also found that a fraction of M1 associated with cellular membranes [3].

Analytical, diagnostic and therapeutic context of M1

• By immunoprecipitation, NS2-M1 complexes were also detected in virus-infected cell lysates [6].
• Circular dichroism showed that the C-terminal part of M1 contained helical structure [7].
• In vitro dissection of the membrane and RNP binding activities of influenza virus M1 protein [4].

References