Researchers from University of British Columbia have identified a common ancestral gene that enabled the evolution of advanced life over a billion years ago and without which, the life on our planet would probably still be bacterial slime.
The gene, found in all complex organisms including plants and animals, encodes for a large group of enzymes known as protein kinases that enabled cells to be larger and to rapidly transfer information from one part to another.
"If the duplications and subsequent mutations of this gene during evolution didn't happen, then life would be completely different today," said Steven Pelech, professor in the UBC faculty of medicine.
Plants, animals, mushrooms and more all exist because they are made up of eukaryotic cells that are larger and far more complex than bacteria.
Inside of these eukaryotic cells are hundreds of organelles that perform diverse functions to keep them living, just as different organs do for the human body.
The new research, published in the Journal of Biological Chemistry, identifies the gene that gave rise to protein kinases.
On a cellular scale, these highly interactive signaling proteins play a role similar to the neurons in the brain by transferring information throughout the cell by a process known as protein phosphorylation.
This ability to transmit signals from one part of the cell to another not only enabled cells to become more complex internally, but also allowed cells to come together to form systems, paving the way for the evolution of intelligent life.
Research into these enzymes has become very important to medicine.
More than 400 human diseases like cancer and diabetes are linked to problems with cell signalling.
Disease occurs when a cell gets misinformed or confused and today, about one-third of all pharmaceutical drug development is targeted at protein kinases.
From sequencing the genomes of humans, scientists knew that about 500 genes for different protein kinases all had similar blueprints.
"Our new research revealed that the gene probably originated from bacteria for facilitating the synthesis of proteins and then mutated to acquire completely new functions," added Pelech.
The findings can help study other important protein families and could eventually lead to the creation of a protein version of the evolutionary tree of life.
