Monoclonal Antibody #3‐9‐16 Recognizes One of the Two Isoforms of Rabies Virus Matrix Protein That Exposes Its N‐Terminus on the Virion Surface

Abstract

The envelope of rabies virus (a prototype member of the Rhabdovirus family) contains two kinds of major viral proteins, a transmembrane glycoprotein (G) and a matrix protein (M; formerly called M2), as well as some other host-derived minor components such as CD44 and CD99-related glycoprotein (VAP21) (11,(23)(24)(25). The M protein is a small-sized nonglycosylated internal protein (24-kDa), and is thought to be located underneath the lipid bilayer of the viral envelope where the protein is associated in some way with both the viral G protein and ribonucleoprotein (RNP) (26). Although the M protein is one of the major viral envelope components, detailed studies on the M protein have not been so frequently

Characterization of a Slow‐Migrating Component of the Rabies Virus Matrix Protein Strongly Associated with the Viral Glycoprotein

“…5 (lane 5), anti-M mAb #3-9-16 much more efficiently precipitated the 54-kDa component than the monomer forms. As already shown in our previous study (1), if the reaction time for anti-M mAb and M antigens was shortened from 2 hr to 1 hr, the amount of precipitated M protein monomers was decreased by 30-40%, while that of the dimer was not affected (data not shown), implicating that the M protein dimers are taking the β-form (i.e., N-terminalexposed conformation).…”

“…On the other hand, only a small fraction of the monomer was recognized by the mAb if the reaction time was limited to 0.5-1 hr (data not shown), indicating that the 3-9-16 epitope region is mostly hidden inside in the case of the monomer form, but is exposed occasionally by conformational change of the M protein as described previously (1). Recognition of the monomer by mAb #3-9-16 was quite increased in the presence of DOC as seen in Fig.…”

“…Our data suggest that the N-terminal epitope region is exposed on a dimer form of the M protein molecule, and was efficiently recognized by a mAb #3-9-16 that recognized an N-terminal-located linear epitope of the M protein. On the other hand, only a small fraction of the monomer was recognized by the mAb if the reaction time was limited to 0.5-1 hr (data not shown), indicating that the 3-9-16 epitope region is mostly hidden inside in the case of the monomer form, but is exposed occasionally by conformational change of the M protein as described previously (1). Recognition of the monomer by mAb #3-9-16 was quite increased in the presence of DOC as seen in Fig.…”

Membrane and inclusion body targeting of lyssavirus matrix proteins

“…Although we were not able to show Golgi localization for RABV M, colocalization of RABV M from other RABV strains with Golgi apparatus has been reported and it has been suggested that one of two isoforms enables the N‐terminus of M to enter the lumen of the Golgi apparatus (Ameyama et al ., ). Hence, Golgi localization appears not to be a virus species‐specific difference between RABV and EBLV‐1 M but more likely represents a general feature of lyssaviruses that may vary between different virus isolates or strains.…”

Produção de anticorpos monoclonais para caracterização de variantes antigênicas brasileiras de vírus da raiva.

“…A forma maior M representando 70-75% da proteína M do virion e a forma Mβ, menor, representando 25 a 30% do virion (Conzelmann, et al, 1990;Ameyama et al, 2003;Wunner, 2007). Aproximadamente 1200-1500 proteínas M se ligam ao core RNP, condensando-o e formando o arcabouço do virion.…”