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Researchers at the Consejo Superior de Investigaciones Científicas (CSIC) have identified a new plant models mechanism by which cells regulate the expression of their genes. The finding, with potential applications in genetic engineering, it helps to clarify the evolutionary differences that separate plants from animals. Research results are published in Proceedings of the National Academy of Sciences USA.

Specifically, researchers Maria de la Paz Sanchez, and Crisanto Gutierrez, who worked at the Centro de Biología Molecular Severo Ochoa (CSIC joint center and the Autonomous University of Madrid), have studied the ORC1 protein, which has a crucial role in the initiation of replication of the genome in all eukaryotic organisms (a group that includes plants, animals and fungi, among others). It also serves as a regulator of expression of certain genes.

The authors found that ORC1 the model plant Arabidopsis thaliana serves as an activator of gene expression rather than as a repressor of the same, as in yeast and human cells. "This is a completely unexpected finding because the ORC1 proteins from Arabidopsis and human are highly conserved evolutionarily from one another and therefore was expected to have the same function," says Gutierrez.

What is the reason for the difference? Researchers have concluded that the key lies in a group of amino acids that is organized in three dimensions a feature called PHD domain, which is present in vegetable protein ORC1, but not in human cells.

"All plants, including algae, possess a PHD domain in their corresponding proteins ORC1. Therefore, the mechanism described in this investigation appears to be general in nature to the whole large group of plant organisms. This helps to understand the differences regulation of gene expression between plants and other eukaryotic organisms, "explains researcher CSIC.

The finding is interesting from the standpoint of epigenetics, a discipline that studies changes in the genome without changing the genetic code. These alterations, different from the mutations that alter DNA sequences and involved in the onset of diseases such as cancer or the problems of embryonic development, are highly influenced by the action of external agents.

Gutierrez extends this point: "The discovery helps in the field of epigenetics to understand why plants and animals, which have highly conserved proteins among themselves and the same types of modifications of histones [evolutionarily highly conserved protein that associated andalusia DNA, Chromatin up], they are able to interpret some epigenetic modifications differently. "

Among other applications, the results of the work can be the basis for better understanding the functioning of protein modules, such as ORC surveyed in this research. Advance their knowledge base is to make combinations or exchanges of modules with protein to make certain proteins that gain activity not previously owned. In this sense, the authors suggest, a very attractive possibility is the design of molecular switches that act as activators or repressors of the activity of certain genes.