Disease relevance of M1

• A bicistronic mRNA transcribed from the influenza B virus RNA segment 7 encodes two viral proteins, matrix protein M1 and uncharacterized small protein BM2 [1].
• Crystal structure of the M1 protein-binding domain of the influenza A virus nuclear export protein (NEP/NS2) [2].
• Antiviral activity of influenza virus M1 zinc finger peptides [3].

High impact information on M1

• The NEP-M1 interaction involves two critical epitopes: an exposed tryptophan (Trp78) surrounded by a cluster of glutamate residues on NEP, and the basic nuclear localization signal (NLS) of M1 [2].
• Previous nucleotide sequence analysis of RNA segment 7 of influenza B virus indicated that, in addition to the reading frame encoding the 248 amino acid M1 protein, there is a second overlapping reading frame (BM2ORF) of 585 nucleotides that has the coding capacity for 195 amino acids [4].
• A single amino acid change in the C-terminal domain of the matrix protein M1 of influenza B virus confers mouse adaptation and virulence [5].
• The deduced amino acid sequence of the M1 protein indicates that it contains 248 amino acids of which 243 are identical in the B/Lee/40 M1 protein [6].

Biological context of M1

• The influenza B virus BM2 protein contains 109 amino acid residues and it is translated from a bicistronic mRNA in an open reading frame that is +2 nucleotides with respect to the matrix (M1) protein [7].

References