Influenza virus matrix protein 1 (M1 protein)

Influenza virus matrix protein 1 (M1 protein) is the most abundant structural protein of influenza virus particles[1][2][5][6]. It lines the inner surface of the viral envelope, forming a shell or endoskeleton that maintains virion integrity and mediates particle stability. M1 is a bifunctional protein with membrane and RNA-binding capabilities and consists of two domains (N-terminal and C-terminal) connected by a flexible linker[1][4][6]. The N-terminal domain is α-helical, while the C-terminal domain also contains helical elements[6]. M1 coordinates several key steps in the viral lifecycle, including assembly and budding of new virions, encapsidation of viral ribonucleoproteins, and interaction with other viral surface proteins (hemagglutinin, neuraminidase)[1][2][3][7]. It regulates the export of viral genetic material from the nucleus and inhibits viral transcription in host cells[1][3]. Oligomerization of M1 at the membrane is essential for particle formation; structural studies reveal complex mechanisms for its assembly and pH-triggered disassembly upon cell entry[2][5][6]. The protein is a central focus for antiviral strategies aimed at blocking virus assembly or uncoating, although no approved drugs directly target M1 as of now[6][9].

Other names

Influenza virus M1 proteinMatrix protein M1Influenza A virus M1 protein

Drugs targeting M1 aim to disrupt matrix layer assembly, virus budding, or entry by interfering with M1 oligomerization or its interactions with lipids, RNA, or other viral proteins