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Title: Membrane fractions active in poliovirus RNA replication contain VPg precursor polypeptides

The poliovirus specific polypeptide P3-9 is of special interest for studies of viral RNA replication because it contains a hydrophobic region and, separated by only seven amino acids from that region, the amino acid sequence of the genome-linked protein VPg. Membraneous complexes of poliovirus-infected HeLa cells that contain poliovirus RNA replicating proteins have been analyzed for the presence of P3-9 by immunoprecipitation. Incubation of a membrane fraction rich in P3-9 with proteinase leaves the C-terminal 69 amino acids of P3-9 intact, an observation suggesting that this portion is protected by its association with the cellular membrane. These studies have also revealed two hitherto undescribed viral polypeptides consisting of amino acid sequences of the P2 andf P3 regions of the polyprotein. Sequence analysis by stepwise Edman degradation show that these proteins are 3b/9 (M/sub r/77,000) and X/9 (M/sub r/50,000). 3b/9 and X/9 are membrane bound and are turned over rapidly and may be direct precursors to proteins P2-X and P3-9 of the RNA replication complex. P2-X, a polypeptide void of hydrophobic amino acid sequences but also found associated with membranes, is rapidly degraded when the membraneous complex is treated with trypsin. It is speculated that P2-X is associated with membranes bymore » its affinity to the N-terminus of P3-9.« less
Authors:
; ; ;
Publication Date:
OSTI Identifier:
6267082
Resource Type:
Journal Article
Resource Relation:
Journal Name: Virology; (United States); Journal Volume: 128
Research Org:
State Univ. of New York, Stony Brook
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; CELL MEMBRANES; STRUCTURAL CHEMICAL ANALYSIS; POLIO VIRUS; NUCLEIC ACID REPLICATION; AMINO ACID SEQUENCE; ANTIBODIES; BIODEGRADATION; ENZYMES; HELA CELLS; MOLECULAR BIOLOGY; POLYPEPTIDES; RADIOIMMUNOASSAY; RNA; TRYPSIN; CELL CONSTITUENTS; CHEMICAL REACTIONS; DECOMPOSITION; HYDROLASES; ISOTOPE APPLICATIONS; MEMBRANES; MICROORGANISMS; MOLECULAR STRUCTURE; NUCLEIC ACIDS; ORGANIC COMPOUNDS; PARASITES; PEPTIDE HYDROLASES; PEPTIDES; PROTEINS; RADIOASSAY; SERINE PROTEINASES; TRACER TECHNIQUES; VIRUSES 550201* -- Biochemistry-- Tracer Techniques