Two mRNAs that differ by two nontemplated nucleotides encode the amino coterminal proteins P and V of the paramyxovirus SV5

Abstract

The "P" gene of the paramyxovirus SV5 encodes two known proteins, P (Mr approximately equal to 44,000) and V (Mr approximately equal to 24,000). The complete nucleotide sequence of the "P" gene has been obtained and is found to contain two open reading frames, neither of which is large enough to encode the P protein. We have shown that the P and V proteins are translated from two mRNAs that differ by the presence of two nontemplated G residues in the P mRNA. These two additional nucleotides convert the two open reading frames to one of 392 amino acids. The P and V proteins are amino coterminal and have 164 amino acids in common. The unique C terminus of V consists of a cysteine-rich region that resembles a cysteine-rich metal binding domain. An open reading frame that contains this cysteine-rich region exists in all other paramyxovirus "P" gene sequences examined, which suggests that it may have important biological significance.

Sequence comparison between the phosphoprotein mRNAs of human and bovine respiratory syncytial viruses identifies a divergent domain in the predicted protein

“…This insertion did not create a frameshift. Similarly, insertions have been found in the P mRNAs of simian virus 5 (Thomas et al, 1988), measles virus (Cattaneo et al, 1989), Sendal virus (Vidal et al, 1990a) and mumps virus (Paterson & Lamb, 1990). The P gene of these viruses gives rise to two mRNA species: one is an exact copy of the genome, whereas the other contains G residue insertions within a stretch of three to six G residues.…”

Conserved Cysteine-Rich Domain of Paramyxovirus Simian Virus 5 V Protein Plays an Important Role in Blocking Apoptosis

“…The V/P gene of SV5 is transcribed into both the V mRNA and the P mRNA through a process (commonly called "RNA editing") of pseudo-templated addition of nucleotides (53). The V mRNA is transcribed when the viral RNA polymerase faithfully transcribes the V/P gene.…”

“…The V protein C-terminal domain contains seven cysteine residues (resembling a zinc finger domain) and binds atomic zinc (31,40,48,53). The V protein of SV5 interacts with soluble nucleocapsid protein (41), and the N-terminal domain of V binds RNA through a basic region (29).…”

Involvement of the Zinc-Binding Capacity of Sendai Virus V Protein in Viral Pathogenesis

“…The colinear transcript encodes the P protein as well as the C, CЈ, Y 1 , and Y 2 proteins; these four proteins are translated in a shifted frame by alternative translational starts. The P gene also directs synthesis of an accessory mRNA for the V protein by inserting a pseudotemplated G residue at the specific editing site (30,31). Consequently, the V and P proteins have the same 317 residues at the amino terminus (the P/V common region), while the V protein contains a 67-residue unique carboxyl terminus (the Vu region).…”