Biomedical subjects

T Tzfira

Publications and source records attributed to T Tzfira.

4 recordsLinked to original sources

PubMed2001

VIP1, an Arabidopsis protein that interacts with Agrobacterium VirE2, is involved in VirE2 nuclear import and Agrobacterium infectivity.

T-DNA nuclear import is a central event in genetic transformation of plant cells by Agrobacterium. This event is thought to be mediated by two bacterial proteins, VirD2 and VirE2, which are associated with the transported T-DNA molecule. While VirD2 is imported into the nuclei of plant, animal and yeast cells, nuclear uptake of VirE2 occurs most efficiently in plant cells. To understand better the mechanism of VirE2 action, a cellular interactor of VirE2 was identified and its encoding gene cloned from Arabidopsis. The identified plant protein, designated VIP1, specifically bound VirE2 and allowed its nuclear import in non-plant systems. In plants, VIP1 was required for VirE2 nuclear import and Agrobacterium tumorigenicity, participating in early stages of T-DNA expression.

Amino Acid Sequence↗

PubMed2001

Genetic transformation of HeLa cells by Agrobacterium.

Agrobacterium tumefaciens is a soil phytopathogen that elicits neoplastic growths on the host plant species. In nature, however, Agrobacterium also may encounter organisms belonging to other kingdoms such as insects and animals that feed on the infected plants. Can Agrobacterium, then, also infect animal cells? Here, we report that Agrobacterium attaches to and genetically transforms several types of human cells. In stably transformed HeLa cells, the integration event occurred at the right border of the tumor-inducing plasmid's transferred-DNA (T-DNA), suggesting bona fide T-DNA transfer and lending support to the notion that Agrobacterium transforms human cells by a mechanism similar to that which it uses for transformation of plants cells. Collectively, our results suggest that Agrobacterium can transport its T-DNA to human cells and integrate it into their genome.

Agrobacterium tumefaciens↗

PubMed2000

Nucleic acid transport in plant-microbe interactions: the molecules that walk through the walls.

Many microbes "genetically invade" plants by introducing DNA or RNA molecules into the host cells. For example, plant viruses transport their genomes between host cells, whereas Agrobacterium spp. transfer T-DNA to the cell nucleus and integrate it into the plant DNA. During these events, the transported nucleic acids must negotiate several barriers, such as plant cell walls, plasma membranes, and nuclear envelopes. This review describes the microbial and host proteins that participate in cell-to-cell transport and nuclear import of nucleic acids during infection by plant viruses and Agrobacterium spp. Possible molecular mechanisms by which these transport processes occur are discussed.

Biological Transport↗

PubMed1998

Genetic engineering for cut-flower improvement.

The application of modern biotechnological approaches to cut flowers has clearly become instrumental and rewarding for the floriculture industry. In recent years, several gene-transfer procedures have been developed for some of the major commercial cut flowers. Using Agrobactrium or microprojectile bombardment, several basic protocols are now available. However, despite the great progress and interest in gene transfer to these crops, their transformation is routine in only a limited number of laboratories, and its application is still considered to be an "art form". This review summarizes the reported gene-transfer procedures for the main cut-flower crops, with an emphasis on the unique factors of each method and the recent progress in introducing new traits of horticultural interest into these species.

Journal Article↗