Influenza Matrix 1 / M1

Influenza A virus matrix protein M1 is one of the most important and abundant proteins in the virus particles broadly involved in essential processes of the viral life cycle. The matrix protein M1 protein is membrane associates and forms a rigid matrix layer under the viral envelope utilizing multiple protein-lipid and protein-protein interactions. M1 protein is a candidate antigen for a broad-spectrum influenza virus vaccine and the adjuvant chitosan significantly improved the efficacy of the M1 vaccine.


Influenza Matrix 1 Structure

M1 is a structurally polarized molecule with a highly-ordered NM-fragment and a potentially unstructured C-terminal domain. The M1 protein consists of 252 amino acid residues with a calculated molecular mass (MM) based on the amino acid sequence of ,28 kDa. Numerous attempts to crystallize and solve the structure of full length M1 have been unsuccessful and consequently no high resolution model exists for the entire protein. The crystal structure of the 18 kDa NM domain (amino acids 1-164) has been determined at pH 4. Unfortunately, crystallographic studies have not yet provided structural information about the C-terminal domain of M1.

Influenza Matrix 1 Function

Influenza A virus matrix protein M1 plays essential structural and functional roles in the virus life cycle. Influenza virions M1 protein forms a well ordered helical layer adjacent to the viral envelope, and the close interaction of M1 with the surrounding envelope determines the virion morphology.The rigid matrix layer of M1 maintains the integrity and shape of the intact influenza virus and structurally organises the virus membrane. M1 provides the basement and an anchor point for the HA fusion machinery.


Influenza Matrix 1 Reference

• Eleonora V. Shtykova.Structural Analysis of Influenza A Virus Matrix Protein M1 and Its Self-Assemblies at Low pH.PLOS ONE.2013
• Nancy Hom.Deep Mutational Scan of the Highly Conserved Influenza A Virus M1 Matrix Protein Reveals Substantial Intrinsic Mutational Tolerance.Journal of Virology.2019
• David Saletti.The Matrix protein M1 from influenza C virus induces tubular membrane invaginations in an in vitro cell membrane model.Scientific Reports.2017
• Ismail Dahmani.Influenza A matrix protein M1 induces lipid membrane deformation via protein multimerization.Bioscience Reports.2019.

Influenza Virus Antigen Information