Interaction between the open reading frame III product and the coat protein is required for transmission of cauliflower mosaic virus by aphids.

Aphid transmission of cauliflower mosaic virus requires the viral PIII protein.

The open reading frame (ORF) III product (PIII) of cauliflower mosaic virus is necessary for the infection cycle but its role is poorly understood. We have used in vitro protein binding ('far Western') assays to demonstrate that PIII interacts with the cauliflower mosaic virus (CaMV) ORF II product (PII), a known aphid transmission factor. Aphid transmission of purified virions of the PII-defec...

A second cauliflower mosaic virus gene product influences the structure of the viral inclusion body.

We have used electron microscopy of thin sections and experiments on isolated viroplasms to compare the properties of four strains of cauliflower mosaic virus (CaMV), three of which were partially or completely deleted in open reading frame (ORF) II. Our results confirm that this gene is required for aphid transmissibility and show that the product of ORF II influences the firmness with which v...

Nuclear targeting of the cauliflower mosaic virus coat protein.

The entry of the viral genomic DNA of cauliflower mosaic virus into the nucleus is a critical step of viral infection. We have shown by transient expression in plant protoplasts that the viral coat protein (CP), which is processed from the product of open reading frame IV, contains an N-terminal nuclear localization signal (NLS). The NLS is exposed on the surface of the virion and is thus avail...

Molecular Properties of Bari 1, a Mild Strain of Cauliflower Mosaic Virus

We studied aspects of the structure and expression of the genome of Bari 1, a mild strain of cauliflower mosaic virus. Differences were observed between gene products of Bari 1 detected in inclusion body preparations and those of the more typically severe strain, Cabb B-JI. The most striking difference was the gel mobility of the Bari 1 gene VI polypeptide (apparent Mr 70K) which contrasted wit...

Partial Epitope Mapping of Alfalfa mosaic Virus and the Effect of Coat Protein Gene Mutation on Aphid Transmission