Expression und Charakterisierung des Andes-Virus L-Proteins

Abstract

Andes virus (ANDV) is a member of the genus Hantavirus. Little is known about structure and function of the hantaviral L protein. Sequence alignments revealed a putative RNA-dependent RNA polymerase domain in the center and an endonuclease at the N terminus. Studying hantaviral L proteins is difficult, because recombinant L protein expression in mammalian cells is very ineffective. Deletion analysis revealed that the N terminus determine the low-expression phenotype. This work demonstrates that ANDV L protein expression can be rescued upon mutation of catalytic amino acids and further conserved residues of the putative endonuclease domain. In addition, wild-type ANDV L rather than expressible L mutants suppressed the level of mRNA and reduces protein expression. Expressible ANDV L mutants colocalized with the cellular processing (P) bodies, ANDV N and NSs protein, but not with the glycoprotein Gc. This work suggests that ANDV L protein possesses an endonuclease at the N terminus suppressing the level of its own as well as heterologous mRNAs upon recombinant expression in mammalian cells.