Researchers have identified specific gene sites controlled by global regulator GABPa are linked to the development of metabolic and cognitive conditions, such as Alzheimer’s disease. The study, “Human lineage-specific transcriptional regulation through GA binding protein transcription factor alpha (GABPa),” was published in the journal Molecular Biology and Evolution.
Differences in gene regulation have long been regarded as the main contributors for the phenotypic differences in closely related species. Despite this knowledge, few examples of evolutionary changes in gene regulation have been demonstrated and verified. Researchers investigated the global gene regulator transcription factor GABPa and its binding sites to determine possible evolutionary changes and adaptations in the human lineage.
This regulator has great genomic influence, controling genes in all primates, mice, dogs and cows. This influence has been attributed to a tandem repeat in the DNA code: the four letters GGAA. Through experiments in human cell lineages, the scientists identified 11,619 GABPa binding sites, representing nearly 4,000 genes, and compared their sequences with binding sites from 34 other mammals, identifying 224 human-specific GABPa binding sites. Moreover, by introducing human GABPa binding sites into primate cells, researchers observed that gene expression was significantly increased, indicating the human mutations in GABPa resulted in higher gene expression, probably driving evolutionary changes in humans.
Further analysis of the data revealed that a significant amount of the GABPa gene regulatory sites were enriched in genes important for brain and spinal cord development and functions, linking the transcription factor to cognitive disorders such as autism, Parkinson’s disease, Alzheimer’s disease and diabetes.
“Mutations that cause changes in the regulation of gene activities are one of the major factors in shaping species during evolution,” corresponding author Robert Querfurth said in a press release. “Our study demonstrates how, out of the millions of DNA regions in which we differ from other apes, we can sift out those that … cause gene activity changes in human cells. In this set, we find genes involved in brain and breast development and also in diseases like Alzheimer’s and Parkinson’s.”