A host protein (La) binds to a unique species of minus-sense leader RNA during replication of vesicular stomatitis virus.

Abstract

Baby hamster kidney (BHK) cells infected with the minus-strand RNA virus vesicular stomatitis virus (VSV) contained 3 small viral leader RNA species of the minus sense. The longest-minus-strand leader RNA was 54 nucleotides long and was complexed with the host cell La protein that was immunoprecipitated by antisera from patients with systemic lupus erythematosus. The La protein is normally found associated with RNA polymerase III transcripts in their unprocessed form. Shorter minus-strand leader RNA species of 45-48 nucleotides were more abundant but were not associated with the La protein. Unlike the plus-strand leader RNA of VSV, the minus-strand leader RNA were not detected in the nucleus in any form. The minus-strand leader RNA accumulated gradually throughout infection and could not be found in association with the viral nucleocapsid protein. The sequence required for La protein binding on the 54-nucleotide-long minus-strand leader is similar to that at the 3'' end of the La protein binding-plus-strand leader RNA. Thus, a role for the La protein in the replication of VSV is proposed.