Structural highlights
Function
[M2_I72A2] Forms a proton-selective ion channel that is necessary for the efficient release of the viral genome during virus entry. After attaching to the cell surface, the virion enters the cell by endocytosis. Acidification of the endosome triggers M2 ion channel activity. The influx of protons into virion interior is believed to disrupt interactions between the viral ribonucleoprotein (RNP), matrix protein 1 (M1), and lipid bilayers, thereby freeing the viral genome from interaction with viral proteins and enabling RNA segments to migrate to the host cell nucleus, where influenza virus RNA transcription and replication occur. Also plays a role in viral proteins secretory pathway. Elevates the intravesicular pH of normally acidic compartments, such as trans-Golgi network, preventing newly formed hemagglutinin from premature switching to the fusion-active conformation (By similarity).[1]
Publication Abstract from PubMed
The transmembrane domain of the M2 protein from influenza A virus forms a nearly uniform and ideal helix in a liquid crystalline bilayer environment. The exposure of the hydrophilic backbone structure is minimized through uniform hydrogen bond geometry imposed by the low dielectric lipid environment. A high-resolution structure of the monomer backbone and a detailed description of its orientation with respect to the bilayer were achieved using orientational restraints from solid-state NMR. With this unique information, the tetrameric structure of this H(+) channel is constrained substantially. Features of numerous published models are discussed in light of the experimental structure of the monomer and derived features of the tetrameric bundle.
Structure of the transmembrane region of the M2 protein H(+) channel.,Wang J, Kim S, Kovacs F, Cross TA Protein Sci. 2001 Nov;10(11):2241-50. PMID:11604531[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Holsinger LJ, Nichani D, Pinto LH, Lamb RA. Influenza A virus M2 ion channel protein: a structure-function analysis. J Virol. 1994 Mar;68(3):1551-63. PMID:7508997
- ↑ Wang J, Kim S, Kovacs F, Cross TA. Structure of the transmembrane region of the M2 protein H(+) channel. Protein Sci. 2001 Nov;10(11):2241-50. PMID:11604531
